INSIDE THIS ISSUE: Challenge Problems Head’s Message Comings & Goings New Faculty/Staff University of Massachusetts Amherst 2018-2019 Volume 34 Awards Student Awards Dinner Departmental Events TEACHING MATH IN PRISONS Applied Math Master’s Projects The following article was published in the Notices of the American Mathematical Society December 2019, and gives a summary of Annie Raymond’s extensive activities in teaching mathematics to in- Donors carcerated people – Ed.
Teaching inmates college-level mathematics has been one of the most important and rewarding ex- Mathematics and Statistics periences of my career so far. I started in 2016 when I was a postdoc at the University of Washington. The math department received an email from University Beyond Bars (UBB), a local nonprofit that offers college classes to inmates at the Monroe Correctional Complex. The email asked if anyone in the department would agree to volunteer to teach Math 104 (Finite Math) or Math 106 (College Algebra) at the prison.
I had no idea that some prisons offered university-level classes, but my interest was piqued. As a kid, the elementary school I attended consisted of children from the nearby housing projects as well as children from middle-class families. I saw no difference between the kids who came from more af- fluent families, and those who didn’t. Each kid was some unique combination of smart, funny and kind. Still, despite all of us being the same as kids, many of the kids from the projects got caught in the Professor Emeritus crushing cycle of poverty, and some ended up spending some time in prison. Thinking about all of the Floyd Williams potential that had been wasted as a result of structures in place in our society, I volunteered to teach Math 104. Article continues on page 13
ALUMNI PROFILE
Mike Lopez received an MS in Statistics from our department in 2010. After a PhD at Brown he has made his way to Director of Data and Analytics at the National Football League. He will visit the department in April 2020. As a taster, John Staudenmayer Professor Nate Whitaker interviewed him by email. MATHEMATICALLY Q. You have the kind of job that quantitatively oriented sports fans GIFTED AND BLACK dream of. Can you describe how you ended up in your current posi- tion? Department head Nate Whi To be honest, this definitely was not my dream job – whenever I would taker and Professor Emeritus have been dreaming about jobs, this specific role would not have been Floyd Williams are among the around. But with more and more data in the game than ever before, these types of roles are popping 28 honorees chosen to fea up across sport organizations. As one insight into the current NFL, all players have RFID chips in ture on the website Mathe their shoulder pads that track each movement on the field, at roughly 10 frames per second. That’s matically Gifted and Black. a substantial amount of data for us to learn from. Nate’s talk in Fall 2019 to the Primarily, our job is to use football data to make the game better. That starts with on-field data, department Math Club on his including game quality, long term changes, and rules changes, and we also touch on officiating, journey from the shadow of health and safety, and pace of play trends. But we likewise want to grow the overall impact of data segregation to his current po in the game as well, so we are in charge of events that help serve core football fans who want to learn sition was well attended and more about the game, and who want to play with the data themselves. Article continues on page 19 very moving. 1. Find all values of the real parameter a, for which the equation
log 6 x 5 18 = 2 + 3 log 2 + 2 log 3 a | − |− a a has exactly two real roots. 2. Prove that for any x, y, z 0, we have MATHEMATICS & 2019 CHALLENGE≥ PROBLEMS (1 + x + y + z)2 4(1 + x2 + y2 + z2). ≤ STATISTICS 1. Find all values of the real parameter a, for which the equation When isNEW the inequality CHALLENGE strict? PROBLEMS log 6 x 5 18 = 2 + 3 log 2 + 2 log 3 NEWSLETTER a | − |− a a MATHEMATICS & 3. Show thatHere the is equation a selection of some of the more challenging 1. hasFind exactly all values two of real the roots. real parameterx2 + 19a,x for whichy2 =0 the equation problems from the 2018 Jacob-Cohen-Killam− prize STATISTICS 2. Prove that for anylogx, y,6 zx 0,5 we18 have= 2 + 3 log 2 + 2 log 3 has onlyexam. one positive Threea integral additional| ≥− |− solution prize (x, yaexam) and findaproblems it. are EDITED BY 2 2 2 2 (1 + x + y + z) 4(1 + x + y + z ). NEWSLETTERMark C. Wilson 4. A parallelepipedhasincluded exactly two isin real a the roots.polyhedron Awards ≤ with Dinner six faces, article each on of page which 14. is.. a parallel- ogram.2. WhenProve Consider thatis the for inequality any a vertexx, y, strict?z of0, wea parallelepiped have and the diagonal line segment ...... ≥ 3. Show that the equation from the vertex to the(1 + oppositex + y + z)2 vertex.4(1 + x Let2 + yd2 +bez2) the. length of the diagonal. EDITED BY x2 + 19≤x y2 =0 SupposeProblem that, as in 1 the. Compute figure, the the− three volume edges meetingof the 2018– at the vertex have When is the inequality strict? lengthhasdimensionala1 only, a2 one, and positivea3 simplex integraland their solution angles (x, y) andto the find it. diagonal are θ1, θ2, and θ3, Richard S. Ellis Robert Kusner respectively.3.4. ShowA parallelepiped that Show the equation that is a polyhedron with six faces, each of which is a parallel- 20182 2 ogram. Consider a vertex ofx a parallelepiped+ 19x y =0 and the diagonal line segment {(t1, ... , t2018 R −t1 t2018 . hasfrom only the one vertex positive to thed integral= oppositea1 cos solution vertex.θ1 + (ax,2 Let ycos) andd θbe2 find+ thea it. length3 cos θ of3. the diagonal. Suppose...... that, as in the figure, the three edges meeting at the vertex have DESIGNED BY 4. Alength parallelepipeda1, a2, and is)∈ a3 polyhedronand their : 0 angles with ≤ six to faces,≤ the ··· diagonal each ≤ of whichare θ 1≤, isθ 21} a, parallel- and θ3, ogram.respectively. Consider Show a that vertex of a parallelepiped and the diagonal line segment fromProblem the vertex to 2. the Given opposite vertex.numbers Let d bea1 the, a2 length, a3, ofa4 the, suppose diagonal. Brigette McKenna Suppose that, as ind the= a figure,1 cos θ1 the+ a three2 cos θ edges2 + a3 meetingcos θ3. at the vertex have an is defined recursively as length a1, a2, and a3 and their angles to the diagonal are θ1, θ2, and θ3, respectively. Show that a = (a + a + a + a )/4. With special thanks to: Eduardo Cattani, Paul n n−1 d = a1n−2cos θ1 +n−3a2 cos θ2 +n−4a3 cos θ3. IN COOPERATION WITH Hacking, Rob Kusner, Alejandro Morales, Ivan Mirkovic, Jenia Tevelev, Ilona Trousdale, Show that the sequence {an} converges and Q.Y. CHEN P. FLAHERTY O. GWILLIAM named contributors, and those whose names 5. Let xn calculatebe one of theL = numbers limn→∞ froman. ... the...... following sequence: P. HACKING are J.forgotten HOROWITZ but whose contributionsS. HROBAR are 5. Let xn be one of the3. numbers3, 33.33 from, 333 the. following333, 3333 sequence:.3333,... V. LYZINSKI greatlyI. appreciated.MIRKOVIC A. MORALES Problem 3.3 .Consider3, 33.33, 333. 333a regular, 3333.3333 tetrahedron,... with F. PEDIT A. RAYMOND C. RUSSELL In other words, xn has 2n decimal digits, all of them equal to 3, In other words, xn has 2n decimal digits, all of them equal to 3, with5. theLetedgesx samen be oneof number oflength the numbers of 1. digits What from before the is following the and length after sequence: the of decimal the shortest point. For every The Department of Mathematics and Statistics with the same number of digits before and after the decimal point. For every N. WANG N. WHITAKER R. YOUNG 2 n, find the first integer larger than2 x . publishes its annual newsletter for alumni and n,loop find the on first its integer surface3.3 larger, 33.33 thanwhich, 333x.n333. n ,surrounds3333.3333,... two vertices? .. friends. You are important, and we want to hear 6. In the process of weaving, vertical threads (warps) are interlaced with horizon- 6. In theIn process..... other...... words,of weaving,xn has vertical 2n decimal threads digits, (warps) all of are them interlaced equal to with 3, horizon- from you! Please contact us at [email protected] tal threadswithtal threads the (wefts). same (wefts). number Every Every of digits warp before and and weft and weft should after should the interlace decimal interlace with point. some Forwith threads every some threads The Department of Mathematics and Statistics publishes n(since, find otherwise the first integer it can How be larger separated thanmanyx from2 . 3×3 the fabric). arrays are there such (since otherwiseProblem it can4. be separatedn from the fabric). its annual newsletterss.edu forto share alumni your news,and friends.let us know You how are you are doing, and learn ways to become involved 6. Inthat the process (i) entries of weaving, include vertical threads all the (warps) digits are interlaced from with1 through horizon- important, and we want to hear from you! Please contact us at tal threads (wefts). Every warp and weft should interlace with some threads with the Department. Our website is a valuable (since9, and otherwise (ii) itentries can be separated in every from row the fabric). and column are in [email protected] to share for current your news, happenings let us and know news, how so increasing order? you are doing, and learn ways to become involved with the we encourage you to visit us regularly at www. Department. Our websitemath.umass.edu. is a valuable resource for current The satin weave, invented in ancient China, depends on integer parameters happenings and news, so we encourage you to visit us regularly a,Problem b > 1. Every 5 time. .Let the warpEn be intersects the coefficients the weft, the places in forthe further intersection will be, for every followingScanned weft, ∞with CamScanner eitherxⁿ an warpsnn! to the left or b at www. math.umass.eduPlease send general feedback to markwilson@ The satinwarpsexpansion: weave, to the right. invented .sec The x picture in+tan ancient illustrates x = China, E the . case ⁿ depends a=0= 2, b on= integer 3 and its parameters The satin weave, invented in ancient China, depends on integer parameters umass.edu, and feedback on challenge problems a, b >standard1. Every weaving time diagram. the warp intersects the weft, the places for further Provea, b > threeShow1. Every statements that time they thefrom warp thesatisfy Anni intersects Albers’ E the= bookE weft, =1On the and Weaving places for: for n further≥1 Scanned0 with CamScanner1 to [email protected] and schaffler@math. intersectionintersection will will be, be, for for every every following followingScanned weft, with CamScanner weft, either eithera warpsa towarps the left to or theb left or b On a more somber note, we mourn the passing on 2 July warpswarps(a) toThe the... to greatest the right. right. common The The picture divisor illustrates of illustratesa and b theshould case the bea caseequal= 2, toab = 1;= 3 2, andb its= 3 and its umass.edu. standard weaving diagram. 2018 of our dear colleague Richard S. Ellis, an internationally standard(b) weavinga + b can be diagram. equal to any positive number except 1, 2, 3, 4, 6. Prove three statements from the Anni Albers’ book On Weaving: Prove three(c) Let statementsn = a+b. Then from lim thef(n)= Anni, where Albers’f(n)book is the numberOn Weaving of possible: regarded probabilist, and a good friend to many of us on n ∞ This year marks a change in editorship. We hope (a) Thesatin greatest weaves withcommon fixed→∞ divisorn. of a and b should be equal to 1; campus and in the tocommunity. maintain the Itstandard’s an immeasurable set by our predecessors. loss to (a) The(b)Problem greatesta + b can be common 6. equal Let to anyA divisorn positive be the of numbera setand of exceptb shouldall 1subsets, 2, 3 be, 4, 6. equal S of to 1; our Department. ForBest many wishes years to all Richard students, editedfaculty, thestaff, annual alumni (c){1,Let 2,n ...,= a n}+b. such Then limthatf(n S)= contains, where f( nthe) is thesize number |S| of possible S. Let (b) a + b can be equal ton any positive∞ number except 1, 2, 3, 4, 6. and friends for 2020! satin weaves with fixed→∞n. Newsletter and monthly News Briefs, and I — your current (c) LetBn be= athe+b. set Then of all lim Sf in(n )=An which, where aref( nminimal) is the number, i.e., of possible n ∞ editor — enjoyed working with him on both for much of the →∞ satinif S weavescontains with some fixed nsubset. T in An then T = S. Show past decade. As I re-drafted the letter soliciting briefs this that the number bn of elements of the set Bn is the th September, I realized it was based on Richard’s traditional n Fibonacci number Fn (here F1 = 1 = F2 and after text, passed down from him to me several years ago. Both that Fn = Fn−1 + Fn−2). this Newsletter and the News Briefs have become Department traditions, shaped by each of us who has taken on the role of Problem 7. Evaluate π/2 1 editor, but Richard’s influence looms large. He and I shared many common interests outside mathematics, particularly an intellectual curiosity about languages and literature, and both Send solutions, comments, or feedback via email of us have been deeply committed to carry on the tradition of to Professor Franz Pedit
2 DEPARTMENT HEAD’S MESSAGE DEPARTMENT HEAD’S MESSAGE I would like to welcome you to our newsletter as Department Head. We have made some exceptional hires and improved our I’d like to welcomegraduate you to and our undergraduate Newsletter programs. as the new Our graduatesDepartment have gone Head. off to I officiallydo outstanding started things. onWe are21 Januaryvery proud of our alumni. 2018. It’s a true honor – and somewhat daunting – to follow in the footsteps of Farshid Hajir, who now serves as ViceA particularProvost areaof Academic of growth is Affairs in our number and didof undergraduate a fantastic job majors in whichhis 3 continuallyyears as Head.exceeds I takeour expectations. over The benefits a department that’sof majoring risen tremendously in math in the 21st in centurystature is since recognized I came more to and UMass more byin our 1987. incoming We’ve students. made Atsome the present we have over 1000 majors. One can choose from seven concentrations, including Actuarial Science, Applied Math, Computing, Pure Math, Statistics, exceptional hires Teachingand improved and an Individual our graduate concentration. and undergraduate Mathematics is alsoprograms. an essential Our part graduates of any degree have at thegone University, on as over 15,000 to do outstandingstudents things. take We’re our classes very proudeach year. of our alumni.
I am pleased to report, thanks for the hard work of our search committee, we have 4 new, outstanding tenure track Assistant A particular area Professors:of growth Maryclare is our number Griffin, ofHaben undergraduate Michael, Leili Shahriyarimajors, whichand Ted continually Westling. Assistant exceeds Professor expectations. Griffin is a More Statistician and more who of our incoming studentsexamines recognize problems thatthe arisebenefits in the contextof majoring of high indimensional math. regression,We have almost where the 1000 number majors of regression in 7 areas: coefficients Actuarial is quiteScience, Applied Math, Computing,large relative Pureto the numberMath, Statistics,of observations. Teaching Assistant and Professor an Individual Haben Michael concentration. is a Statistician Mathematics specializing in problemsis also an arising essential part of any 21st centuryin HIV monitoringeducation, and as treatment, over 15,000 in particular UMass the students complications take introduced our classes in modeling each year. HIV longitudinal data and diagnostics from repeated experiments. Assistant Professor Leili Shahriyari is an Applied Mathematician and Math Biologist who develops in- novative frameworks to systematically employ a combination of machine learning and statistical methods as well as mathematical Thanks to the hardtechniques work toof arriveour search at personalized committee, cancer therapies.our tenure Assistant track Professorposition Ted in WestlingMath Biologyis a Statistician was filledspecializing by ourin developingtop candidate: Assistant Professorsemiparametric Brian Van efficiency Koten is antheory expert and nonparametricin applied probability statistical methods and numerical in causal analysis analysis, and survivalperforming analysis. computer We also had a simulations of molecularvery successful systems year inwith hiring applications 5 new outstanding in biology, Visiting chemistry Assistant Professors: and materials Chris Elliot, science. Tina Kanstrup,We also Rafaelhad a Montezuma, very successful Padhy Budhinath and Mithun Thudiyangal. In addition, we hired 2 new permanent lecturers: Maria Correia and Garret Cahill. year in hiring 8 newLast outstandingbut not least, Mark Visiting Wilson Assistant joined us as Professors: a Visiting Associate Siddhant Professor, Agrawal and has, takenPanagiota up the job Birmpa of newsletter, Noriyuki editor. Hamada, Kuan-Wen Lai, Jonathan Simone, Zahra Sinaei, Zheni Utic and Jiayu Zhai. Our new Marshall Stone VAP, Laura Colmenarejo Hernando, will joinThe usnewsletter in Spring allows 2019. the department to highlight some of the outstanding work of our faculty in pushing the envelopes of knowl- edge in Mathematics and Statistics each year. The National Science Foundation recently awarded a collaborative $ 1.5 million grant to the College of Information and Computer Sciences and our department to further develop the foundations of data science in a Our Newsletter, andproject the that on-line will create Faculty an NSF News national Briefs institute at www.math.umass.edu, at UMass. Markos Katsoulakis provide and Patrick an opportunity Flaherty are Co-PIs to highlight on the grant some and of the outstanding workAnna Liuof our and Lucfaculty Rey-Bellet in pushing are senior the researchers envelope on ofthe knowledge grant. Patrick inFlaherty mathematics and Leili Shahriyari and statistics were awarded each year: NIH grants. Assistant Professor Nestor AndreaGuillen Nahmod spoke is ata PI the for Austina Simons workshop Foundation Collaborative“Gerrymandering Grant studying Steals wave Elections: turbulence. Learn Professor how Jenia It’s TevelevDone receivedand How a to Fulbright Scholar Award to Chile. Tevelev is conducting research and lecturing at Universidad Catolica de Chile as part of a project Stop It,” and was calledpart of“New a panel Frontiers on ofthe Algebraic topic including Geometry”. USKrista Representative Gile received the Jim College’s McGovern Outstanding this Teaching year; Associate Award. Daeyoung Professor Kim Paul Hacking was invitedreceived to lecturethe same ataward the in 2018 2018, International a fact omitted from Congress the previous of Mathematicians;newsletter. Associate Professor Alexei Oblomkov was awarded a Simons Fellowship; Professors Markos Katsoulakis and Luc Rey-Bellet received a major Air Force grant to develop performance guaranteesOur Colleague in predictive Richard Ellis modeling; passed July Professor2, 2018. The Andrea department Nahmod hosted a conferencewas part in of his a featurehonor on honoringApril 12, 2019, women “Rare Events,in the Notices Information Theory and Statistical Physics”. The distinguished list of speakers were Paul Dupuis (Brown University), Jon Machta of the AMS; and University(UMass Amherst), Distinguished Charles Newman Professor (Courant, Panos NYU), Kevrekidis Peter Otto (Williamette published University), 4 papers Hugo in the Touchette Nature (Stellenbosch family of journals.Univer- sity, South Africa) and Bruce Turkington (UMass Amherst). This past year we hosted 3 conferences in the Department of Mathe- Our Department maticshosted and 3 Statisticsconferences at UMass. this past year: Associate Professor Anna Liu was among the organizers of the 32nd New England StatisticalOn Symposium October 10 and bringing 11, we hosted together our first nearly Baillieul 250 statisticiansDistinguished Lecture.to discuss We wereemerging fortunate issues to have in as April our inaugural 2018; Professorspeaker Andrea NahmodAnthony helped Bloch organize from the Women University in Partialof Michigan. Differential Dr. Bloch gave Equations two excellent in March talks. The 2018; annual and distinguished Associate lecture Professor series Hongkunis sup- Zhang co-organizedported Mathematical by a generous donation Physics by Perspective John Baillieul. of Billards and Dominoes celebrating the 70th birthdays of Pavel Bleher and Leonid Bunimovich in September 2017. Annie Raymond and I co-taught a 3-credit UMass course in finite math at the Hampshire County jail. It was a rewarding experi- ence for us and the inmates. One of the students in a letter stated, What prompted me to take this math course when presented with UMass Amherst undergraduatesthe chance was to be Jonahable to get Chaban off the unit, Artem and split Vysogorets my day up as , aand way toJimmy make it Hwanggo faster. workedHowever, I asdid a notteam, expect led a life by changing Assistant Professor Matthewexperience. Dobson I mean, to producewho loves math the top-scoringbesides Professor project Annie and among Professor 7 competing Nate. I can tell teams you one at thing the it first was not ever easy Studentand I struggled Competition and wanted to give up so many times. No words can express the pride and joy I felt when I was told I passed. I called my son that is Using Modeling (SCUDEM)currently struggling in Fall in school 2017. that Three I his dad justmore passed SCUDEM a math course.teams I led have by a sense Dobson of accomplishment also did very that well I lacked in inSpring me for a2018 very , receiving meritoriouslong time. mention and outstanding mention.
We are very sad toThe have support lost ofan our important alumni and member friends is invaluable of our faculty, to us. WeRichard want to know S. Ellis how , youwho are passed doing. Pleaseaway send in Julyus your 2018. news, Richard or stop joined in for a visit. the department in 1975, and also taught classes in Judaism and the Torah as an adjunct professor of Judaic and Near Eastern Studies. He was an– Nathaniel internationally Whitaker regarded expert in probability and large deviation theory, who also cared very much about the well-being of his students and colleagues, organizing sessions to relieve stress both inside and outside of the classroom. Richard will be truly missed. 2018-19 Volume 34 3 We are also sorry to report the retirement of two important members of our faculty, Michael Lavine and Bill Meeks, in May 2018. Professor Lavine, a well-respected Bayesian statistician and a leader in our statistics group, had been a department member since 2008. Professor Meeks held the prestigious George David Birkhoff chair since joining the department in 1986; he is a world-renowned differential geometer and topologist, with a distinguished reputation in the area of minimal surfaces.
The support of our alumni and friends is invaluable to us. We want to know how you are doing. Please send us your news, or stop in for a visit.
– Nathaniel Whitaker
DEPARTMENT OF MATHEMATICS & STATISTICS 2018 Volume 33 3
3
COMINGS AND GOINGS New Visiting Assistant Professors in 2019 are: Rafael Monte-
THE DEPARTMENT BY THE NEWzuma Cabral, CHALLENGE Chris Elliott, Tina PROBLEMS Kanstrup, Budinath Padhy, NUMBERS (FALL 2019) Mithun Thudiyangel.Also, Laura Colmenarejo started as a MATHEMATICS & HereVAP in is January a selection 2019. of some of the more challenging The department is a large and complex place, problems from the 2018 Jacob-Cohen-Killam prize STATISTICSas you can see from the numbers below. Mark Wilson is a new Visiting Associate Professor on a 4-year exam.contract. Three additional prize exam problems are NEWSLETTERTenure system faculty: 42 included in the Awards Dinner article on page 14... There are 3 new permanent lecturers:Maria Correia, Garret ...... Female tenure system faculty: 8 Cahill, Hyunsun Lee (Mount Ida). EDITED BY . Compute the volume of the 2018– ProblemNew staff: Liming 1 Liu: Administrative Assistant to Head, Terry Visiting Assistant Professors: 17 dimensional simplex Richard S. Ellis Robert Kusner Mullen: Departmental Assistant and Lecturer, Rachel Aronow, {(Research, ... , Computing2018 Facilities. Visiting Associate Professor: 1 t1 t2018 R t1 t2018 .
...... Promotions: Paul Hacking to Full Professor, Anna Liu to Full DESIGNEDLecturers: BY about 23 Professor, Hongkun)∈ Zhang : 0 to ≤ Full Professor,≤ ··· ≤ Matthew ≤ Dobson1} Problemto Associate Professor 2. Given with numbers Tenure, Nestor a1, aGuillen2, a3, ato4 ,Associate suppose Brigette McKenna 27 Professor with Tenure, Sohrab Shahshahani reappointed with Emeritus faculty: an is defined recursively as 4.2 review or Mini-tenure. Staff: 12 Nestoran =Guillen (an−1 and+ a Vincen−2 + aLyzinskin−3 + a aren−4 )/4.on unpaid leave of ab- IN COOPERATION WITH sence. PhD students: 64 Show that the sequence {an} converges and Q.Y. CHEN P. FLAHERTY O. GWILLIAM MS students: 40 calculate L = limn→∞ an...... P. HACKING J. HOROWITZ S. HROBAR NEW FACULTY
V. LYZINSKI I. MIRKOVICFaculty funded A.by MORALES external Leili Shahriyari joined the Department as an Assistant Profes- Problemsor in September 3. Consider2019. She develops a regular innovative tetrahedron frameworks with to F. PEDIT A. RAYMONDresearch grants: C. 16 RUSSELL edgessystematically of length employ 1. aWhat combination is the of length machine of learning the shortest (ML) N. WANG N. WHITAKERUndergraduate majors:R. YOUNG 1007 loopand statistical on its surface methods whichas well as surrounds mathematical two techniques vertices? to .. arrive at unique personalized cancer therapies, which has re-
Students taught 2019-20: .sulted...... in an NIH grant. She received a PhD in mathematics The Department of Mathematics and Statistics publishes about 15000 Problemfrom Johns Hopkins 4. How University, many 3×3 which arrays was followed are there by post such- its annual newsletter for alumni and friends. You are thatdocs (i)at UC entries Irvine andinclude Ohio Stateall the University. digits Atfrom Irvine 1 throughshe de- important, and we want to hearRegular from you! seminar Please series: contact about us at 14 9,veloped and (ii)stochastic entries models in every to improve row understanding and column of cellare dy in- [email protected] to share your news, let us know how namics during tumorigenesis, and worked on artificial neural increasingnetwork models order? for obtaining gene regulatory networks. Before you are doing, and learn waysFloors to become of Lederle involved graduate with the joining UMass, she was Assistant Professor at University of Tex- Department. Our website isResearch a valuable Tower resource containing for current our as Arlington. happenings and news, so we encourage you to visit us regularly Problem 5. .Let En be the coefficients in the faculty: 8 ∞ xⁿ n at www. math.umass.edu expansion:Haben Michael . secjoined x+tan the department x = E as. ⁿan n =0assistant n! professor Extra wings of LGRT proposed in September 2019. His research mainly lies in the field of causal Show that they satisfy E0 =E1 =1 and for n≥1 by administration that we occupy inference. Causal inference develops methods to infer causal re- On a more somber note, we mourn the passing on 2 July lationships... without the benefit of fully randomized experiments. 2018 of our dear colleague Richard“soon”: S. 2Ellis, an internationally regarded probabilist, and a good friend to many of us on The field has always been of consequence to the social sciences, campus and in the community. It’s an immeasurable loss to where randomization Let Ais often be the available, set of and all is subsets increasingly S of rel - Problemevant to the tech6. world,n where large amounts of observational our Department. For many years Richard edited the annual {1,data 2, are ..., now n} suchavailable that for Sanalysis. contains Haben’s the methodssize |S| haveof S ex. Let- Newsletter and monthly News Briefs, and I — your current Bn be the set of all S in An which are minimal, i.e., editor — enjoyed working with him on both for much of the if S contains some subset T in An then T = S. Show past decade. As I re-drafted the letter soliciting briefs this that the number bn of elements of the set Bn is the 4 DEPARTMENT OF MATHEMATICS & STATISTICS th September, I realized it was based on Richard’s traditional n Fibonacci number Fn (here F1 = 1 = F2 and after text, passed down from him to me several years ago. Both that Fn = Fn−1 + Fn−2). this Newsletter and the News Briefs have become Department traditions, shaped by each of us who has taken on the role of Problem 7. Evaluate π/2 1 editor, but Richard’s influence looms large. He and I shared many common interests outside mathematics, particularly an intellectual curiosity about languages and literature, and both Send solutions, comments, or feedback via email of us have been deeply committed to carry on the tradition of to Professor Franz Pedit
2 DEPARTMENT HEAD’S MESSAGE I’d like to welcome you to our Newsletter as the new Department Head. I officially started on 21 January 2018. It’s a true honor – and somewhat daunting – to follow in the footsteps of Farshid Hajir, who now serves as Vice Provost of Academic Affairs and did a fantastic job in his 3 years as Head. I take over a department that’s risen tremendously in stature since I came to UMass in 1987. We’ve made some exceptional hires and improved our graduate and undergraduate programs. Our graduates have gone on to do outstanding things. We’re very proud of our alumni.
A particular area of growth is our number of undergraduate majors, which continually exceeds expectations. More and more of our incoming students recognize the benefits of majoring in math. We have almost 1000 majors in 7 areas: Actuarial Science, Applied Math, Computing, Pure Math, Statistics, Teaching and an Individual concentration. Mathematics is also an essential part of any 21st century education, as over 15,000 UMass students take our classes each year.
Thanks to the hard work of our search committee, our tenure track position in Math Biology was filled by our top candidate: Assistant Professor Brian Van Koten is an expert in applied probability and numerical analysis, performing computer simulations of molecular systems with applications in biology, chemistry and materials science. We also had a very successful year in hiring 8 newThe departmentoutstanding welcomed Visiting 4 newAssistant Assistant Professors: Professors in Siddhant September Agrawal2019: from ,left Panagiota to right in theBirmpa photo,, LeiliNoriyuki Shahriyari, Hamada , Kuan-Wen Lai, JonathanHaben Michael, Simone Ted Westling,, Zahra Maryclare Sinaei, ZheniGriffin. Utic and Jiayu Zhai. Our new Marshall Stone VAP, Laura Colmenarejo Hernando, will join us in Spring 2019. tended instrumental variable methods and often draw on semi- Maryclare Griffin joined the department as an assistant pro- parametric theory to produce efficient and robust tools. Haben fessor in September, 2019. Her research interests include high Our Newsletter, andreceived the hison-line PhD in Faculty Statistics Newsfrom Stanford Briefs Universityat www.math.umass.edu, in 2017 dimensional provide regression an problems, opportunity mixed tomodels, highlight and methods some of the outstanding workunder ofthe our supervision faculty of in Lu pushing Tian and Ingramthe envelope Olkin. of knowledgefor spatio-temporal in mathematics data. and statistics each year: Assistant Professor Nestor Guillen spoke at the Austin workshop “Gerrymandering Steals Elections: Learn how It’s Done and How to Stop It,” and was partBefore of coming a panel to UMasson the he topic spent including two years as US a post-doctor Representative- Maryclare Jim grewMcGovern up in Massachusetts this year; and Associate is happy to Professor be back after Paul Hacking was invitedal fellow, to lecture split between at the Harvard’s 2018 International Biostatistics and Congress Wharton’s of Mathematicians;about a decade living Associate in other states. Professor Maryclare Alexei received Oblomkov a PhD was awarded a SimonsStatistics Fellowship; departments, Professors under the Markos supervision Katsoulakis of Eric Tchetgen. and Lucin statisticsRey-Bellet from thereceived University a major of Washington Air Force in Seattle grant in 2018to develop performance guarantees in predictive modeling; Professor Andrea Nahmodand recently was completed part of aa short feature postdoc honoring at Cornell women University. in the Notices Ted Westling joined the department as an Assistant Professor of the AMS; and University Distinguished Professor Panos Kevrekidis published 4 papers in the Nature family of journals. in September 2019. His primary research interests lie in de- veloping nonparametric statistical theory and methods, often DEPARTMENTAL STAFF OVERVIEW nd Our Department appliedhosted to 3 problemsconferences arising this in causalpast year:inference Associate and survival Professor Anna Liu was among the organizers of the 32 New England Statisticalanalysis Symposium with observational bringing data.together In all nearlyhis work, 250 Ted statisticians aims to We to currently discuss have emerging twelve staff issues members in inApril the department. 2018; Professor They Andrea Nahmodunderstand helped organize when and Women how machine in Partial learning Differential methods can beEquations are: Rachel in March Aronow 2018; and Alan and Boulanger Associate in ResearchProfessor Comput Hongkun- Zhang co-organizedused Mathematicalas part of the process Physics of achieving Perspective valid large-sample of Billards staand- Dominoesing Facilities, celebrating Carla Mokrzecki, the 70 Naitianth birthdays Wang, andof PavelKam KitBleher and Leonid Bunimovichtistical in inference.September 2017. Wong in the Business Office, Liming Liu in the Department Head’s Office, Jacob Lagerstrom in Academic Advising, and Ted received his PhD in statistics from the University of Wash- Lisa Bergman, Cathy Russell, Terry Mullen, Sarah Willor, and UMass Amherst undergraduatesington in 2018 under Jonah the supervision Chaban of, MarcoArtem Carone. Vysogorets Prior to , andIlona Jimmy Trousdale Hwang in Academic worked Scheduling as a team, and Support. led by Assistant Professor Matthewjoining Dobson UMass,, to he produce was a postdoctoral the top-scoring researcher inproject the Center among 7 competing teams at the first ever Student Competition Using Modeling (SCUDEM)for Causal Inference in Fall at theUniversity 2017. Three of Pennsylvania. more SCUDEM There, teamshe Two led long-time by Dobson staff alsomembers did left very the well department in Spring in Summer2018, receiving meritoriousworked mention with Dylan and Small outstanding to develop causal mention. inference methods 2018. Director of Research Computing Facilities Ken Pollard, for continuous exposures. He also worked with faculty from who worked in the department for over 20 years and oversaw We are very sad tothe have Perelman lost anSchool important of Medicine member and the ofChildren’s our faculty, Hospital Richard many S.changes Ellis and, who improvements passed away to our in IT July operations, 2018. Richard retired joined the department inof 1975,Philadelphia and also to develop taught and classes apply statistical in Judaism methodology and the to Torahin July as 2018. an adjunct He is currently professor living ofin Hadley,Judaic MA,and whereNear he Eastern is Studies. He was anthe internationallyanalysis of pediatric regarded infectious diseases.expert in probability and involvedlarge deviation in many community theory, whoactivities also and cared enjoying very his much retire- about the well-being of his students and colleagues, organizing sessions to relieve stress both inside and outside of the classroom. Richard will be truly missed. 2018-19 Volume 34 5 We are also sorry to report the retirement of two important members of our faculty, Michael Lavine and Bill Meeks, in May 2018. Professor Lavine, a well-respected Bayesian statistician and a leader in our statistics group, had been a department member since 2008. Professor Meeks held the prestigious George David Birkhoff chair since joining the department in 1986; he is a world-renowned differential geometer and topologist, with a distinguished reputation in the area of minimal surfaces.
The support of our alumni and friends is invaluable to us. We want to know how you are doing. Please send us your news, or stop in for a visit.
– Nathaniel Whitaker
DEPARTMENT OF MATHEMATICS & STATISTICS 2018 Volume 33 3
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ment. Assistant to the Department Head Christine Mirabal, who Applications are currently being accepted for the Fall 2020 class. was with the department for almost 5 years, also left in July 2018. More information on the program is available at: http://www. She is now working for the Art Department at Amherst College. math.umass.edu/graduate/statistics NEW CHALLENGE PROBLEMS MATHEMATICSWe’ve added several staff members & since Summer 2018, as well. – Erin Conlon As we mentioned in our last newsletter, Naitian Wang joined Here is a selection of some of the more challenging STATISTICSthe department as our new Business Manager in August 2018. problems from the 2018 Jacob-Cohen-Killam prize Naitian holds Bachelor’s and Master’s Degrees in Accounting exam. Three additional prize exam problems are DEPARTMENTAL CLIMATE COMMITTEE NEWSLETTERand was previously the Associate Director of Financial Services included in the Awards Dinner article on page 14... in the School of Education...... The Department of Mathematics and Statistics’ Climate Com- mittee is dedicated to understanding and improving the pro- EDITED BY Liming Liu became our new Assistant to the Department Head Problemfessional climate 1. Computeof our department. the volume The committee of the 2018– includes in October 2018. Liming holds Master’s degrees in both Sociol- dimensionalrepresentatives fromsimplex the faculty, staff, graduate student, and
Richard S. Ellisogy and Political Robert Science Kusner and previously worked on campus undergraduate student populations, and is working to sys- {( , ... , 2018 in the Provost’s office. She also teaches college level courses in tematicallyt1 t2018 reviewR and improvet 1the experiencest2018 of all these.
Chinese Language and Popular Culture and is a member of the ...... groups. DESIGNEDInternational Language BY Institute of Massachusetts. )∈ : 0 ≤ ≤ ··· ≤ ≤ 1}
ProblemIn the 2018-2019 2. academicGiven numbers year, the Climate a1, a Committee2, a3, a4, suppose started BrigetteMore recently, McKenna Terry Mullen joined the department in March this work by beginning the process of systematically reviewing an is defined recursively as 2019 to provide much needed support with Academic Schedul- the experiences of all department members. The committee ing. Terry is a 2017 graduate of our Master’s program in Applied created a climate feedback bulletin board, where department an = (an−1 + an−2 + an−3 + an−4)/4. Mathematics and is also a lecturer for the department in AY members could leave anonymous comments related to climate. IN COOPERATION2019-20. WITH The committee also took up the task of surveying the graduate Showstudent that body the and sequencereceiving detailed {an} convergesfeedback about and its experi- Q.Y. CHEN P.Rachel FLAHERTY Aronow became theO. newest GWILLIAM Research Computing Facili- calculateence. Since Lthis = limsurvey,n→∞ a a Graduaten...... Student Advisory Council P. HACKING J.ties HOROWITZ staff member in May 2019.S. HROBARRachel is also a graduate of the de- has been created to coordinate graduate student input in de- partment’s Applied Mathematics Master’s program, class of 2019. V. LYZINSKI I. MIRKOVIC A. MORALES partmental matters and improve the graduate student experi- Problemence. This group 3. Considerhas created newa regular academic tetrahedron and social events with for F. PEDIT A. RAYMOND C. RUSSELL We’re currently searching for a newly created Career and Aca- edgesgraduate of students. length It1. will What use fundsis the secured length by of the the 2018-2019 shortest N. WANG N.demic WHITAKER Advising staff position,R. YOUNGand we hope that we’ll soon be loopClimate on Committee its surface to organizewhich surroundspre-talks before two departmental vertices? .. able to fill a vacancy in Research Computing Facilities. seminars. The Graduate Student Advisory Council will also be ...... –Ilona Trousdale, Director of Administration and Staff working with the 2019-2020 Climate Committee to create a new The Department of Mathematics and Statistics publishes Problemmentoring program 4. How for graduatemany 3×3students. arrays are there such its annual newsletter for alumni and friends. You are that (i) entries include all the digits from 1 through important, and we want to hear from you! Please contact us at 9,The and 2019-2020 (ii) entries Climate in Committee every row is continuing and column the work are start in- [email protected] toNEW share M.S. your OPTIONnews, let usIN knowSTATISTICS how IN THE ed last year by surveying the undergraduate students. In addi- increasingtion, the committee order? is working to create more opportunities for you are doing, and learnBOSTON ways to become AREA, involved STARTING with FALL the 2019 undergraduate students to interact informally with faculty. The Department. Our website is a valuable resource for current committee is working to gain a broader awareness and under- In the Fall of 2019, the University of Massachusetts Amherst be- . .Let E be the coefficients in the happenings and news, so wegan encourageoffering the youM.S. optionto visit in usStatistics regularly in the Boston area at the Problemstanding of climate 5 issuesn within the department, and will use ∞ xⁿ n at www. math.umass.eduMount Ida campus in Newton, under the direction of Associate expansion:this information .sec to xplan+tan new x trainings= E . forⁿ n department=0 n! mem- Professor Erin Conlon. bers,Show improve that communication they satisfy in E the = department,E =1 and and for create n≥1 a more effective department website.0 We are1 grateful to be part of On a more somber note,This we programmourn is the an eveningpassing program. on 2 JulyThere are six graduate a department... that cares about the well-being and inclusion of all 2018 of our dear colleaguestatistics Richard courses S. Ellis, being anoffered internationally for the 2019-2020 academic year, departmental members, and we look forward to continuing to regarded probabilist, andwith a moregood to friendbe added toin futuremany years. of usThe on current-year courses learn about and improve the climate of our department. include Mathematical Statistics I and II, Statistical Computing, campus and in the community. It’s an immeasurable loss to Problem– Krista Gile and6. Let Victoria A beDay the set of all subsets S of Regression Modeling, Statistical Methods for Data Science, and n our Department. For many years Richard edited the annual Design of Experiments. {1, 2, ..., n} such that S contains the size |S| of S. Let Newsletter and monthly News Briefs, and I — your current Bn be the set of all S in An which are minimal, i.e., editor — enjoyed working with him on both for much of the if S contains some subset T in An then T = S. Show past decade. As I re-drafted the letter soliciting briefs this that the number bn of elements of the set Bn is the 6 DEPARTMENT OF MATHEMATICS & STATISTICS th September, I realized it was based on Richard’s traditional n Fibonacci number Fn (here F1 = 1 = F2 and after text, passed down from him to me several years ago. Both that Fn = Fn−1 + Fn−2). this Newsletter and the News Briefs have become Department traditions, shaped by each of us who has taken on the role of Problem 7. Evaluate π/2 1 editor, but Richard’s influence looms large. He and I shared many common interests outside mathematics, particularly an intellectual curiosity about languages and literature, and both Send solutions, comments, or feedback via email of us have been deeply committed to carry on the tradition of to Professor Franz Pedit
2 ANDREA NAHMOD NEWS Hispanic/Latinx NSF-funded investigators for Hispanic Heri- tage Month (October 2018). DEPARTMENT Professor HEAD’SAndrea R. Nahmod MESSAGE was invited by The Norwegian I’d like to welcomeAcademy you to of our Science Newsletter and Letters as asthe a guestnew ofDepartment Professor Karen Head. I officially started on 21 January 2018. It’s a true honorK. Uhlenbeck – and for somewhat the Abel Prize daunting Ceremonies – to that follow took placein the in footsteps of Farshid Hajir, who now serves as ViceOslo Provost in May of2019. Academic The events Affairs included anda dinner did fora fantastic mathema- job in his 3 years as Head. I take over a department that’sticians risen at thetremendously Norwegian Academy in stature of Sciences since and I came Letters; to the UMass in 1987. We’ve made some exceptional hires Abeland Prizeimproved Ceremony our (attended graduate by theand King undergraduate of Norway) at the programs. Our graduates have gone on University of Oslo’s Aula Magna, the Abel Lectures, the Norwe- to do outstandinggian things. Government’s We’re very Abel Prizeproud banquet of our with alumni. the King of Norway at Akershus Castle and the Abel Prize party at the Norwegian A particular area Academyof growth of Sciences is our andnumber Letters. of undergraduate majors, which continually exceeds expectations. More and more of our incoming students recognize the benefits of majoring in math. We have almost 1000 majors in 7 areas: Actuarial Science, Applied Math, Computing,Andrea is a PI Pure of the Math, team thatStatistics, was awarded Teaching this year and the an Si -Individual concentration. Mathematics is also an essential part of any 21st centurymons Foundation education, Collaboration as over 15,000 in Mathematical UMass studentsand Physical take our classes each year. Sciences grant to tackle Wave Turbulence. This is a four year 8M grant with possibility of extension for another three years. Thanks to the hard work of our search committee, our tenure track position in Math Biology was filled by our top candidate: This collaboration is a joint effort of several groups of leading Assistant Professorresearchers Brian Vanin mathematics Koten is andan expertphysics, inin the applied US and probability the EU, and numerical analysis, performing computer simulations of molecularfor a systematic systems coordinated with applications study of wave turbulence in biology, in a chemistry large Photo and via materialswww.windy.com science. We also had a very successful year in hiring 8 newscale outstanding project. The collaboration Visiting Assistant director is JalalProfessors: Shatah from Siddhant the Agrawal, Panagiota Birmpa, Noriyuki Hamada, Kuan-Wen Lai, JonathanCourant Institute Simone at NYU., Zahra The Sinaei team’s, Zheniwebsite is: Utic https://cims. and Jiayu Zhai. Our new Marshall Stone VAP, Laura Colmenarejo Hernando, will joinnyu.edu/wave-turbulence/ us in Spring 2019. GILE & KIM WIN COLLEGE TEACHING AWARD Andrea was featured (one of 27 women mathematicians) in Our Newsletter, and the on-line Faculty News Briefs at www.math.umass.edu,Krista Gile provide was one of an two opportunity awardees for Outstanding to highlight Teaching some of the Notices of the American Mathematical Society as part of in the College of Natural Sciences annual CNS Outstanding the outstanding workWomen’s of ourHistory faculty Month, in pushingMarch 2018, the Volume envelope 65, Issueof knowledge 03 in mathematics and statistics each year: Assistant Achievement Awards in May 2019. The citation states: Professor Nestor andGuillen further spoke selected at by the the AustinAMS Public workshop Awareness “Gerrymandering Office to be Steals Elections: Learn how It’s Done and How to
Stop It,” and was partprofiled of ain panel a special on poster the topicfor the including MathFest, SIAM,US Representative and AMS Jim McGovern this year; Associate Professor Paul Professor Gile has distinguished herself at all facets of her Hacking was invitedsectional to lecture meetings at andthe displayed2018 International at 2019 JMM, Congress Baltimore, of Mathematicians; Associate Professor Alexei Oblomkov was professional activities. She uses the relationships that she MD. She was also one of 8 PIs featured by the NSF’s Office of awarded a Simons Fellowship; Professors Markos Katsoulakis and Luc Rey-Belletbuilt in service received to organizations a major (including Air Force UNAIDS, grant US to develop Legislative and Public Affairs (OLPA) in Medium’s issue on performance guarantees in predictive modeling; Professor Andrea NahmodCDC, Vietnamwas part CDC, of a US feature State Department) honoring to women advance in the Notices of the AMS; and University Distinguished Professor Panos Kevrekidis publishedthe careers of 4 herpapers students. in theKrista Nature is an excellent family academic of journals. with a worldview that leads her to support humanitari- Our Department hosted 3 conferences this past year: Associate Professoran effortsAnna Liuwith herwas unique among and strongthe organizers skills as a statisti of -the 32nd New England Statistical Symposium bringing together nearly 250 statisticians cian.to discuss She founded emerging a statistics issues working in groupApril involving 2018; Professorstu- Andrea Nahmod helped organize Women in Partial Differential Equationsdents in and March faculty 2018; across andcampus. Associate Graduate Professor students find Hongkun Zhang co-organized Mathematical Physics Perspective of Billards and Dominoesthis working celebrating group extremely the valuable70th birthdays in their training. of Pavel Bleher and Gile is especially passionate about the statistics consulting Leonid Bunimovich in September 2017. center, giving high quality statistical service to individ- uals while at the same time teaching students the art of UMass Amherst undergraduates Jonah Chaban, Artem Vysogorets, andconsulting. Jimmy SheHwang is exceptionally worked good as a at team, weaving led together by Assistant Professor Matthew Dobson, to produce the top-scoring project among 7lectures competing that reach teams all levels at theof students first inever the classroom,Student Competition Using Modeling (SCUDEM) in Fall 2017. Three more SCUDEM teams facilitatingled by Dobson an open alsoenvironment did very for collaborationwell in Spring and 2018, receiving meritorious mention and outstanding mention. questions.
Daeyoung Kim won the same award the previous year, a fact We are very sad toThe have Abel lost Prize an banquet important at Arkershus member Castle of with our Karen faculty, Richard S. Ellis, who passed away in July 2018. Richard joined the department in 1975, and also taught classes in Judaism and the Torahunfortunately as an adjunct omitted professorfrom the previous of Judaic issue and of this Near newslet Eastern- Uhlenbeck (center) ter. Congratulations Daeyoung and Krista! Studies. He was an internationally regarded expert in probability and large deviation theory, who also cared very much about the well-being of his students and colleagues, organizing sessions to relieve stress both inside and outside of the classroom. Richard will be truly missed. 2018-19 Volume 34 7 We are also sorry to report the retirement of two important members of our faculty, Michael Lavine and Bill Meeks, in May 2018. Professor Lavine, a well-respected Bayesian statistician and a leader in our statistics group, had been a department member since 2008. Professor Meeks held the prestigious George David Birkhoff chair since joining the department in 1986; he is a world-renowned differential geometer and topologist, with a distinguished reputation in the area of minimal surfaces.
The support of our alumni and friends is invaluable to us. We want to know how you are doing. Please send us your news, or stop in for a visit.
– Nathaniel Whitaker
DEPARTMENT OF MATHEMATICS & STATISTICS 2018 Volume 33 3
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NSF DATA SCIENCE FUNDING successful team funded $1.8M over 2 years to study the relation between brain structure and social behavior of humans, using The National Science Foundation (NSF) recently awarded a col- fMRI data, online experiments, and data analysis and simula- laborative team led by Andrew McGregor (computer science, NEWtion. Other CHALLENGE team members come PROBLEMSfrom Harvard, Stony Brook, UMass). This is a three-year, $1.5 million grant to further devel- Albany, Chicago, and Minnesota. MATHEMATICSop the foundations of data science & in a project that will create Here is a selection of some of the more challenging STATISTICSNSF’s national TRIPODS Institute for Theoretical Foundations problems from the 2018 Jacob-Cohen-Killam prize of Data Science. exam. Three additional prize exam problems are NEWSLETTER OTHER AWARDS Also part of the executive committee with McGregor are Mar- included in the Awards Dinner article on page 14... kos Katsoulakis and Patrick Flaherty of our department, and ...... Jenia Tevelev has received a Fulbright U.S. Scholar Program EDITEDLuc Rey-Bellet BY is listed as a senior researcher. award to research. Compute and lecture atthe Universidad volume Catof Óthelica 2018–de Chile Problemin Santiago during 1 the 2019-2020 academic year, as part of a dimensional simplex Richard S. EllisOne aspect of Robert the TRIPODS Kusner project will be to organize summer project called “New Frontiers of Algebraic Geometry.” Jenia schools, speaker series, talks by experts in related technical ar- {(therebyt , ... adds, t to hisR collection2018 of tawards, whicht also contains. a Sloan1 Fellowship,2018 UMass Research1 Leadership 2018in Action award eas and workshops for faculty researchers in other disciplines ...... who want to learn how big data can help them. and a Simons Fellowship! DESIGNED BY )∈ : 0 ≤ ≤ ··· ≤ ≤ 1}
Problem 2. Given numbers a , a , a , a , suppose BrigetteUnlike McKennathe “practical outcomes” focus of some big data initia- Pat Flaherty was recently awarded a three-year,1 2 $582,8833 4 grant tives, the focus of TRIPODS is more on theoretical, mathemat- afromn is definedthe National recursively Institutes of Health’sas (NIH) National Insti- ical and foundational aspects of data science. The TRIPODS tute of General Medical Sciences to better understand cellular
team aims to mathematically prove attributes of a given algo- proteinan =homeostasis, (an−1 + a n−2the +balance an−3 + between an−4)/4. protein creation and IN COOPERATIONrithm such as running WITH time, accuracy and scalability. destruction. The dysregulation of protein homeostasis is one Showof the primarythat the paths sequence that allows {a diseases} converges such as andAlzheimer’s, Huntington’s or Parkinson’s to develop.n Pat is an expert on Q.Y. CHEN P.Data FLAHERTY sets in the sciences, suchO. asGWILLIAM genetics and physics, are grow- calculate L = lim a ...... ing larger every year. For example, a personalized medical de- statistical tools used n→∞to analyze n large genomic data sets. He is P. HACKING J. HOROWITZ S. HROBAR vice may generate data continuously, 24 hours a day and seven collaborating on this award with Peter Chien, professor of bio- V. LYZINSKI I. MIRKOVIC A. MORALES chemistry and molecular biology, who is an expert on the highly days a week, over a year or longer. Problem 3. Consider a regular tetrahedron with F. PEDIT A. RAYMOND C. RUSSELL regulated cellular cleanup system in which specialized proteins McGregor says, “In statistics the more data you get, the more edgescalled proteases of length degrade 1. What damaged is theor no-longer-needed length of the proteins shortest N. WANG N. WHITAKER R. YOUNG accurate you can be, but in computer science the more data you loopa system on critical its surface for protein which homeostasis. surrounds They two plan vertices?to develop .. get, the longer it will take you to process. That’s one reason you new. statistical and computational tools to analyze large-scale .genetic...... experiments to catalog the essential components of this The Department of Mathematicsneed computer andscientists Statistics and mathematicians publishes working togeth- er. When you double the size of the input, we need to know Problemsystem, which 4. Flaherty How andmany Chien 3×3 hope arrays will lead are to there better unsuch- its annual newsletter forif the alumni algorithm andtakes twicefriends. as long, You four aretimes as long or 100 thatderstanding (i) entries of pathways include important all the for digits many humanfrom diseases.1 through important, and we want totimes hear as fromlong? That’s you! Pleaseimportant.” contact us at 9, and (ii) entries in every row and column are in [email protected] to share your news, let us know how increasingLeili Shahriyari order? has recently been awarded an NIH Grant for you are doing, and learnThe ways award to isbecome part of the involved foundation’s with $17.7 the million support for “Data-Driven QSP Software for Personalized Colon Cancer Department. Our website12 isTransdisciplinary a valuable resource Research forin Principlescurrent of Data Science Treatment”. QSP models are a system of differential equations (TRIPODS) projects, which will bring together the statistics, that model the dynamic interactions between drug(s) and a bi- happenings and news, so we encourage you to visit us regularly Problem 5. .Let En be the coefficients in the mathematics and theoretical computer science communities at ological system. These mathematical ∞ xⁿ models providen an inte- expansion: .sec x+tan x = E . ⁿ n=0 n! at www. math.umass.edu14 institutions in 11 states to promote long-term research and grated “systems level” approach to determining mechanisms of training activities in data science that transcend traditional dis- action of drugs and finding new ways to alter complex cellular Show that they satisfy E0 =E1 =1 and for n≥1 ciplinary boundaries. networks with mono or combination therapy to obtain effective On a more somber note, we mourn the passing on 2 July treatments.... Since QSP models are a complex system of nonlin- 2018 of our dear colleague Richard S. Ellis, an internationally ear equations with many unknown parameters, estimating the In addition to the TRIPODS program, NSF also has regarded probabilist, andtwo a goodother programsfriend to under many the of usumbrella on of Harness- values of the model’s parameters is extremely difficult. Existing ing the Data Revolution. One of these is the Ideas Lab, parameter estimation methods for QSP models often use as- campus and in the community. It’s an immeasurable loss to Problem 6. Let An be the set of all subsets S of our Department. For manywhich years forms Richard new interdisciplinary edited the annual teams spread across {1,sembled 2, ..., data n} fromsuch various that Ssources contains rather the than size a single |S| ofcurated S. Let institutions. New department member Mark Wilson is part of a dataset. These datasets are usually obtained through various bi- Newsletter and monthly News Briefs, and I — your current Bn be the set of all S in An which are minimal, i.e., editor — enjoyed working with him on both for much of the if S contains some subset T in An then T = S. Show past decade. As I re-drafted the letter soliciting briefs this that the number bn of elements of the set Bn is the 8 DEPARTMENT OF MATHEMATICS & STATISTICS th September, I realized it was based on Richard’s traditional n Fibonacci number Fn (here F1 = 1 = F2 and after text, passed down from him to me several years ago. Both that Fn = Fn−1 + Fn−2). this Newsletter and the News Briefs have become Department traditions, shaped by each of us who has taken on the role of Problem 7. Evaluate π/2 1 editor, but Richard’s influence looms large. He and I shared many common interests outside mathematics, particularly an intellectual curiosity about languages and literature, and both Send solutions, comments, or feedback via email of us have been deeply committed to carry on the tradition of to Professor Franz Pedit
2 ological experiments, in vitro and in vivo animal studies, thus RECOGNITION OF UNDERGRADUATE ACTIVITIES DEPARTMENTrendering HEAD’SQSP models hard MESSAGE to be practicable for personalized treatments. To the best of our knowledge, no QSP model has Honors Research and Theses:Ji-Hun Hwang (Kevrekidis), I’d like to welcomebeen you developed to our Newsletterfor personalized as thecolon new cancer Department treatments. InHead. Alexander I officially Fischer, started Fiona McCann on 21 January(Charalampidis), Jennifer 2018. It’s a true honorthis project, – and we somewhat propose a unique daunting approach – to to follow develop in a theda- footstepsSullivan (Charalampidis), of Farshid Hajir Artem, who Vysogorets (Braden) now serves as Viceta-driven Provost QSP of software Academic to suggest Affairs effective and didtreatment a fantastic for each job Putnam in his Competition:3 years as SunitaHead. IBhattacharya, take over Long Le, Patrick a department that’spatient risen based tremendously on gene expression in stature data from since the primaryI came tumorto UMass Lei, inHaiyao 1987. Liu, We’ve Mridul made Madan, some Nishad Ranade, Daniel Weber, exceptional hires samples.and improved our graduate and undergraduate programs.Aubrey WiederinOur graduates have gone on to do outstanding things. We’re very proud of our alumni. Congratulations to these and other department members re- REU (Research Experience for Undergraduates) Program 2018: A particular area ceivingof growth external is ourresearch number grants. of The undergraduate department continues majors, its whichSponsored continually by Joan Barksdale exceeds (’66),expectations. Sheila R. Flynn, More Nancy and more of upward trajectory in attracting funding. Sinclair and faculty grants. our incoming students recognize the benefits of majoring in math. We have almost 1000 majors in 7 areas: Actuarial Science, Applied Math, Computing, Pure Math, Statistics, Teaching and an IndividualREU in concentration.Pure Math: Jeffrey Mathematics Ayers (Oblomkov), is also anOjaswin essential part of any 21st century education, as over 15,000 UMass students takeKarthikeyan our classes (Williams), each year. Patrick Lei (Schaffler), Matheau Santa- OUTSTANDING STUDENTS HONORED na-Gijzen (Oblomkov), Andrew Sharp (Baykur), Wilson Wang Thanks to the hardAT 2019work of AWARDS our search DINNER committee, our tenure track position(Morales), in Daniel Math Weber Biology (Oblomkov) was filled by our top candidate: Assistant Professor Brian Van Koten is an expert in applied probabilityREU and in Appliednumerical Math analysis,: Katherine performing Donoghue (Charalampidis), computer simulations of molecularThe Awards systems Dinner, with a highly applications anticipated in social biology, event chemistryin the Wenjie and Li (Li),materials Wenbo science.Xie (Q-Y. Chen)We also had a very successful year in hiring 8 newdepartment, outstanding was held Visiting on campus Assistant in April, Professors: organized by Siddhant Paul Agrawal, Panagiota Birmpa, Noriyuki Hamada, Kuan-Wen Lai, JonathanHacking. Simone, Zahra Sinaei, Zheni Utic and JiayuREU Zhai in Statistics:. Our new Collin Marshall Giguere (Flaherty)Stone VAP, Laura Colmenarejo Hernando, will join us in Spring 2019.
Our Newsletter, and the on-line Faculty News Briefs at www.math.umass.edu, provide an opportunity to highlight some of the outstanding work of our faculty in pushing the envelope of knowledge in mathematics and statistics each year: Assistant Professor Nestor Guillen spoke at the Austin workshop “Gerrymandering Steals Elections: Learn how It’s Done and How to Stop It,” and was part of a panel on the topic including US Representative Jim McGovern this year; Associate Professor Paul Hacking was invited to lecture at the 2018 International Congress of Mathematicians; Associate Professor Alexei Oblomkov was awarded a Simons Fellowship; Professors Markos Katsoulakis and Luc Rey-Bellet received a major Air Force grant to develop performance guarantees in predictive modeling; Professor Andrea Nahmod was part of a feature honoring women in the Notices of the AMS; and University Distinguished Professor Panos Kevrekidis published 4 papers in the Nature family of journals.
Our Department Simanhosted Wong, 3 conferences Anwesha Saha this past year:Siman Associate Wong, Peter Professor Delmastro Anna Liu wasSiman among Wong, the Artem organizers Vysogorets of the 32nd New England Statistical Symposium bringing together nearly 250 statisticians to discuss emerging issues in April 2018; Professor Andrea Nahmod helped organize Women in Partial Differential Equations in March 2018; and Associate Professor Hongkun Zhang co-organized Mathematical Physics Perspective of Billards and Dominoes celebrating the 70th birthdays of Pavel Bleher and Leonid Bunimovich in September 2017.
UMass Amherst undergraduates Jonah Chaban, Artem Vysogorets, and Jimmy Hwang worked as a team, led by Assistant Professor Matthew Dobson, to produce the top-scoring project among 7 competing teams at the first ever Student Competition Using Modeling (SCUDEM) in Fall 2017. Three more SCUDEM teams led by Dobson also did very well in Spring 2018, receiving meritorious mention and outstanding mention.
We are very sad toNishad have Ranade, lost an Mridul important Madan, member ofCory our Ward, faculty, Panos Richard Kevrekidis S. Ellis, whoMarkos passed Katsoulakis, away in FionaJuly McCann2018. Richard joined the department inPaul 1975, Hacking, and Sunitaalso taught Bhattacharya, classes in Judaism and the Torah as an adjunct professor of Judaic and Near Eastern Studies. He was anAlexander internationally Fischer regarded expert in probability and large deviation theory, who also cared very much about the well-being of his students and colleagues, organizing sessions to relieve stress both inside and outside of the classroom. Richard will be truly missed. 2018-19 Volume 34 9 We are also sorry to report the retirement of two important members of our faculty, Michael Lavine and Bill Meeks, in May 2018. Professor Lavine, a well-respected Bayesian statistician and a leader in our statistics group, had been a department member since 2008. Professor Meeks held the prestigious George David Birkhoff chair since joining the department in 1986; he is a world-renowned differential geometer and topologist, with a distinguished reputation in the area of minimal surfaces.
The support of our alumni and friends is invaluable to us. We want to know how you are doing. Please send us your news, or stop in for a visit.
– Nathaniel Whitaker
DEPARTMENT OF MATHEMATICS & STATISTICS 2018 Volume 33 3
3
NEW CHALLENGE PROBLEMS MATHEMATICS & Here is a selection of some of the more challenging STATISTICS problems from the 2018 Jacob-Cohen-Killam prize exam. Three additional prize exam problems are NEWSLETTER included in the Awards Dinner article on page 14...... Patrick Lei, Stathis Charalampidis Ji-Hun Hwang, Nate Whitaker Diana Hansen, Nate Whitaker EDITED BY Problem 1. Compute the volume of the 2018– dimensional simplex Richard S. Ellis Robert Kusner 2018 {(t1, ... , t2018 R t1 t2018 ...... DESIGNED BY )∈ : 0 ≤ ≤ ··· ≤ ≤ 1} Given numbers a , a , a , a , suppose Brigette McKenna Problem 2. 1 2 3 4 an is defined recursively as
an = (an−1 + an−2 + an−3 + an−4)/4. IN COOPERATION WITH Anna Liu, Michelle Heeney Markos Katsoulakis, Jinchao Feng, Daniel Weber, Rob Kusner, Katherine Show that the sequence {an} converges and Q.Y. CHEN P. FLAHERTY O. GWILLIAMAnna Liu, Nate Whitaker,calculate Joy Yu, Luc L = limDonoghuea ...... Rey-Bellet n→∞ n P. HACKING J. HOROWITZ S. HROBAR
V. LYZINSKI I.UNDERGRADUATE MIRKOVIC AWARDSA. MORALES Hansen, Jingsheng Huang, Ting-Han Tam, Renée Vartabedian, ProblemNicole White 3. Consider a regular tetrahedron with F. PEDIT A. RAYMOND C. RUSSELL M. K. Bennett Geometry Prize: Thom Barron, Daniel Weber edges of length 1. What is the length of the shortest N. WANG N. WHITAKER R. YOUNG loopThe onSteve its and surface Geni whichMonahan surrounds Student Leadership two vertices? Award: .. Jacob-Cohen-Killam Competition: Sponsored by John Baillieul Jessica Lam, Brenna Walsh (’67), James Francis (’86), and Roy Perdue (’73)...... Outstanding Academic Achievement in Pure Math and Indi- The Department of Mathematics1st Patrick Lei and Statistics3rd Sattwik publishes Das Problem 4. How many 3×3 arrays are there such 2nd Guanghao Wei 4th Shirui Cao and Qisen Luan vidual Concentration: Peter Delmastro, Daniel Weber, Artem its annual newsletter for alumni and friends. You are thatVysogorets, (i) entries Anwesha include Saha all the digits from 1 through important, and we want toSCUDEM hear from Math you! modeling Please contactCompetition: us at Ji-Hun Hwan, 9,Outstanding and (ii) entries Academic in Achievementevery row andin Statistics column: Maxwell are in [email protected] toSharath share Ramkumar, your news, Samuel let us Rosen know how increasingBall, Emily Dzwil, order? Adam Elghazzawi, Michelle Heeney, Zhaoxia you are doing, and learn ways to become involved with the Leon Emory Lincoln and Robert Bradley Lincoln Scholar- Li, Alexandria Sahagian, Edward Schneeweiss, Johnny Wei, Department. Our websiteship: is Patricka valuable Lei resource for current Yingyi Li Problem 5. .Let En be the coefficients in the happenings and news, so weMarcia encourage Lockhart you Ruma to Scholarship: visit us regularly Lewei Ding expansion:Outstanding Academic.sec x+tan Achievement x = ∞ E xⁿ .in ⁿ then=0 Teaching nn! Con- at www. math.umass.edu centration: Eva Gaston, Jessica Gattoni Don Catlin Award for Outstanding Achievement in Applied Show that they satisfy E =E =1 and for n≥1 & Computational Mathematics: Sarah Brockman, Katherine 0 1 On a more somber note,Donoghue, we mourn Robert the Jaycox, passing Matthew on Leblanc,2 July Fiona McCann, GRADUATE... STUDENT AWARDS 2018 of our dear colleagueAlexandre Richard Pelletier, S. Ellis, Andrew an internationally Sharp, Jennifer Sullivan, Chang Distinguished Thesis Award: Jinchao Feng (Katsoulakis regarded probabilist, andYu, a Michael good Zhangfriend to many of us on Rey-Bellet), Cory Ward (Kevrekidis/Whitaker), Joy Yu (Liu) campus and in the community. It’s an immeasurable loss to Let A be the set of all subsets S of The Bob and Lynne Pollack Award for Outstanding Academic ProblemDistinguished 6. Teachingn Award: Sean Hart our Department. For many years Richard edited the annual Achievement in Actuarial Science: Sean Emerson, Diana {1,Graduate 2, ..., n}Student such Leadership that S contains Award: Tori the Day size |S| of S. Let Newsletter and monthly News Briefs, and I — your current Bn be the set of all S in An which are minimal, i.e., editor — enjoyed working with him on both for much of the if S contains some subset T in An then T = S. Show past decade. As I re-drafted the letter soliciting briefs this that the number bn of elements of the set Bn is the 10 DEPARTMENT OF MATHEMATICS & STATISTICS th September, I realized it was based on Richard’s traditional n Fibonacci number Fn (here F1 = 1 = F2 and after text, passed down from him to me several years ago. Both that Fn = Fn−1 + Fn−2). this Newsletter and the News Briefs have become Department traditions, shaped by each of us who has taken on the role of Problem 7. Evaluate π/2 1 editor, but Richard’s influence looms large. He and I shared many common interests outside mathematics, particularly an intellectual curiosity about languages and literature, and both Send solutions, comments, or feedback via email of us have been deeply committed to carry on the tradition of to Professor Franz Pedit
2 LOCAL CONFERENCES of the conference were Laura Colmenarejo, Alejandro DEPARTMENT HEAD’S MESSAGE Morales, Ga Yee Park, Annie Raymond, Jordan Tirrell (now The department organized a few local conferences in the last year. at Washington College), and Ashley Wheeler (Mt. Holyoke) and I’d like to welcome you to our Newsletter as the new Department Head.the Ievent officially received supportstarted from on the21 JanuaryNSF and the UMass MSP 2018. It’s a true honorOn 12 –April and 2019 somewhat the department daunting held – a toconference follow in “Rare the footstepsresearch support of Farshid fund. Hajir, who now serves as ViceEvents, Provost Information of Academic Theory andAffairs Statistical and Physics” did a tofantastic celebrate job in his 3 years as Head. I take over a department that’sour risenlate colleague tremendously Richard Ellis. in stature since I came to UMass– Annie in 1987. Raymond We’ve made some exceptional hires and improved our graduate and undergraduate programs. Our graduates have gone on The speakers were: Paul Dupuis (Brown University), Jon Machta Yao Li, Luc Rey-Bellet and Hongkun Zhang organized and to do outstanding(UMass things. Amherst), We’re veryCharles proud Newman of our(Courant alumni. Institute, NYU), hosted the Second Northeast Conference on Dynamical Sys- Peter Otto (Williamette University), Hugo Touchette (Stellen- tems, held in the department November 15-17 2019. This con- A particular areabosch of growth University, is our South number Africa) and of undergraduateBruce Turkington majors,(UMass whichference continuallywas supported exceedsby NSF grant expectations. DMS-1900397, More and it and con- more of our incoming studentsAmherst). recognize the benefits of majoring in math. centratedWe have onalmost the connection 1000 majors between in dynamical7 areas: Actuarialsystems and Science, Applied Math, Computing, Pure Math, Statistics, Teaching and an Individualmathematical concentration. physics. Mathematics is also an essential part of any 21st centuryRichard’s education, family including as over his 15,000son Michael UMass Ellis studentsattended for take our classes each year. some of the time. This event was supported in part by a generous Two distinguished lectures were given by Giovanni Gallavotti Thanks to the hardcontribution work of of ourAnne search and Peter committee, Costa. our tenure track positionand Konstantin in Math Khanin. Biology Giovanni was filledGallavotti by ourwas topawarded candidate: with Boltzmann Medal in 2007 and Henri Poincare Prize in Assistant Professor Brian Van Koten is an expert in applied probability2018. and He numerical was an ICM analysis, invited speaker performing in 1986 computerand a plenary simulations of molecularMore details systems can be with found applications at: http://people.math.umass.edu/ in biology, chemistry and materials science. We also had a very successful ~nahmod/Rare_Events_InfoTheory_StatsPhysics_Celebrating_ speaker in 1998. Konstantin Khanin was a 2013 Simons Foun- year in hiring 8 newEllis.html outstanding Visiting Assistant Professors: Siddhantdation Agrawal Fellow and, Panagiota an ICM invited Birmpa speaker, Noriyuki in 2018. HamadaHe also , Kuan-Wen Lai, Jonathan Simone, Zahra Sinaei, Zheni Utic and Jiayuheld Zhai the Jean-Morlet. Our new Chair Marshall at the Centre Stone International VAP, Laura de ColmenarejoRen- Hernando, will joinOn April us in 6, Spring2019 the 2019.department hosted the Discrete Math Day contres Mathématiques in 2017. of the Northeast, a biannual regional conference in discrete Our Newsletter, andmath the under on-line the auspicesFaculty of News the NortheastBriefs at www.math.umass.edu,Combinatorics provide an opportunity to highlight some of the outstanding workNetwork. of ourThere faculty were infive pushing speakers: the Diego envelope Cifuentes of knowledge(MIT), FIRST in BAILLIEUL mathematics DISTINGUISHED and statistics each LECTUREyear: Assistant Professor NestorLaura Guillen Colmenarejo spoke at (UMass the Austin Amherst), workshop Pamela Harris “Gerrymandering (Williams Steals Elections: Learn how It’s Done and How to College), Hamed Hatami (McGill), and Lauren Williams A new distinguished lecture series has been established starting Stop It,” and was part of a panel on the topic including US Representative Jim McGovern this year; Associate Professor Paul (Harvard), six poster presentations, and a discussion on math in Fall 2019 through a generous gift by John and Patricia Bail- Hacking was invitedculture. to The lecture conference at the had 2018 a total International of 49 participants Congress including 21of Mathematicians;lieul. Every year, the seriesAssociate will host Professor top researchers Alexei throughout Oblomkov was awarded a Simonswomen Fellowship; and 6 underrepresented Professors Markos minorities. Katsoulakis The local organizers and Luc mathematics Rey-Bellet and receivedstatistics to a disseminate major Air important Force grant recent to de develop- performance guarantees in predictive modeling; Professor Andrea Nahmod was part of a feature honoring women in the Notices of the AMS; and University Distinguished Professor Panos Kevrekidis published 4 papers in the Nature family of journals.
Our Department hosted 3 conferences this past year: Associate Professor Anna Liu was among the organizers of the 32nd New England Statistical Symposium bringing together nearly 250 statisticians to discuss emerging issues in April 2018; Professor Andrea Nahmod helped organize Women in Partial Differential Equations in March 2018; and Associate Professor Hongkun Zhang co-organized Mathematical Physics Perspective of Billards and Dominoes celebrating the 70th birthdays of Pavel Bleher and Leonid Bunimovich in September 2017.
UMass Amherst undergraduates Jonah Chaban, Artem Vysogorets, and Jimmy Hwang worked as a team, led by Assistant Professor Matthew Dobson, to produce the top-scoring project among 7 competing teams at the first ever Student Competition Using Modeling (SCUDEM) in Fall 2017. Three more SCUDEM teams led by Dobson also did very well in Spring 2018, receiving meritorious mention and outstanding mention.
We are very sad to have lost an important member of our faculty, Richard S. Ellis, who passed away in July 2018. Richard joined the department inDMD 1975, attendees and also 2019, taught including classes A. Morales in Judaism (front left), and A. Raymond the Torah (2nd as row an 3rdadjunct from left), professor L. Colmenarejo of Judaic (next and to left), Near G-Y Eastern Park (3 more to left). Studies. He was an internationally regarded expert in probability and large deviation theory, who also cared very much about the well-being of his students and colleagues, organizing sessions to relieve stress both inside and outside of the classroom. Richard will be truly missed. 2018-19 Volume 34 11 We are also sorry to report the retirement of two important members of our faculty, Michael Lavine and Bill Meeks, in May 2018. Professor Lavine, a well-respected Bayesian statistician and a leader in our statistics group, had been a department member since 2008. Professor Meeks held the prestigious George David Birkhoff chair since joining the department in 1986; he is a world-renowned differential geometer and topologist, with a distinguished reputation in the area of minimal surfaces.
The support of our alumni and friends is invaluable to us. We want to know how you are doing. Please send us your news, or stop in for a visit.
– Nathaniel Whitaker
DEPARTMENT OF MATHEMATICS & STATISTICS 2018 Volume 33 3
3
Note that Alexei Oblomkov and Matthew Dobson supervised half of the students between them, an impressive contribution! – Matthew Dobson NEW CHALLENGE PROBLEMS MATHEMATICS & Here is a selection of some of the more challenging STATISTICS problemsSUCCESS from IN INSURANCE the 2018 Jacob-Cohen-Killam MODELING prize exam.COMPETITION Three additional prize exam problems are NEWSLETTER includedTwo doctoral in students the Awards in mathematics Dinner and article statistics, on pageTangxin 14...... Jin and Jie Wang, recently brought home the first place trophy to campus after winning the annual Travelers Analytics Case EDITED BY ProblemCompetition held1. Compute in late January the at volumethe University of the of Connecti 2018–- dimensionalcut Storrs. simplex Richard S. Ellis Robert Kusner 2018 {(Sponsoredt1, ... , t 2018by the insuranceR firm t1headquarteredt2018 in Hartford,. the Inaugural Ballieul Distinguished Lecturer Anthony Bloch ...... competition presented 71 teams of students from UConn’s Storrs DESIGNED(left), donor and BY alumnus John Ballieul (right). and Hartford campuses)∈ as :well 0 ≤ as UMass ≤ ··· Amherst ≤ with ≤ a 1}real-life data set of around 20,000 records with 25 variables each, includ- Problem 2. Given numbers a1, a2, a3, a4, suppose Brigettevelopments McKenna in the field.Dr. Anthony Bloch gave the first Bail- ing such factors as accident reports, driver information, claim an is defined recursively as lieul Distinguished Lecture. He is the Alexander Ziwet Colle- details, vehicle information and location of accident. Their task giate Professor of Mathematics and Department Chair at the was ato use= ( probabilitya + a theory, + a predictive + a )/4.modeling and machine University of Michigan, and he is a leading scholar in the fields learningn to predictn−1 then−2 likelihoodn−3 thatn−4 any given auto accident IN COOPERATIONof geometric mechanics WITH and control of mechanical systems with claim was fraudulent. As Jin explains, “Fraudulent claims are a
symmetry and authored the graduate textbook Nonholonomic Showbig problem that forthe insurance sequence companies {an} converges and mathematical and predic- Q.Y. CHEN P.Mechanics FLAHERTY and Control. HeO. gave GWILLIAM a pair of lectures on Dynam- calculatetive models Lcan = identify limn→∞ cases an. for...... further scrutiny.” P. HACKING J.ics HOROWITZ of Nonholonomic SystemsS. andHROBAR the Geometry of Integrable Systems and Optimal Control, which included demonstrations After months of elimination rounds, three finalist teams, one V. LYZINSKI I. MIRKOVIC A. MORALES of the famous tippe top and rattleback top. Problemfrom each campus, 3. Consider progressed ato regular the last round tetrahedron and were judged with F. PEDIT A. RAYMOND C. RUSSELL by insurance company officers and members of its actuarial and – Matthew Dobson edges of length 1. What is the length of the shortest N. WANG N. WHITAKER R. YOUNG loopadvanced on analyticsits surface teams which on presentation surrounds of their two data vertices? explora- .. tion, model accuracy, cost assessment and business value...... RESEARCH EXPERIENCES FOR The Department of Mathematics and Statistics publishes How many 3×3 arrays are there such UNDERGRADUATES Problem 4. its annual newsletter for alumni and friends. You are that (i) entries include all the digits from 1 through important, and we want toThe hear department’s from you! REU Please program contact recruits us students at from the five 9, and (ii) entries in every row and column are in [email protected] tocolleges share and your pairs news, them letwith us faculty know mentors how for an eight-week increasing order? you are doing, and learnfull ways time to research become project. involved Students with work the either in groups or individually in close collaboration with their faculty mentor. Department. Our websiteTopics is a range valuable throughout resource mathematics for current and statistics depending happenings and news, so we encourage you to visit us regularly Problem 5. .Let En be the coefficients in the on faculty and student interest. This year, we had 14 students ∞ xⁿ n at www. math.umass.eduand 9 faculty members involved. Students had the opportuni- expansion: .sec x+tan x = E . ⁿ n=0 n! ty to present their work during a one day miniconference that Show that they satisfy E =E =1 and for n≥1 was open to schools throughout the area. In addition to UMass, 0 1 On a more somber note,students we mourn from Amherst the passing College, Smithon 2 College, July Williams Col- ... 2018 of our dear colleaguelege, Richard Brown University, S. Ellis, an Yale internationally University, and University of Con- regarded probabilist, andnecticut a good contributed, friend withto many a total ofof 29 us research on presentations campus and in the community.given in parallel It’s an sessions. immeasurable We appreciate loss the to financial support Let A be the set of all subsets S of of Joan Barksdale, which provides research stipends for many ProblemTangxin Jin and 6. Jie Wangn receiving their award for the our Department. For manyof the years students. Richard edited the annual {1,Travelers 2, ..., Analytics n} such Case that Competition. S contains the size |S| of S. Let Newsletter and monthly News Briefs, and I — your current Bn be the set of all S in An which are minimal, i.e., editor — enjoyed working with him on both for much of the if S contains some subset T in An then T = S. Show past decade. As I re-drafted the letter soliciting briefs this that the number bn of elements of the set Bn is the 12 DEPARTMENT OF MATHEMATICS & STATISTICS th September, I realized it was based on Richard’s traditional n Fibonacci number Fn (here F1 = 1 = F2 and after text, passed down from him to me several years ago. Both that Fn = Fn−1 + Fn−2). this Newsletter and the News Briefs have become Department traditions, shaped by each of us who has taken on the role of Problem 7. Evaluate π/2 1 editor, but Richard’s influence looms large. He and I shared many common interests outside mathematics, particularly an intellectual curiosity about languages and literature, and both Send solutions, comments, or feedback via email of us have been deeply committed to carry on the tradition of to Professor Franz Pedit
2 Jin says, “It was a great honor for us to bring the trophy back to TEACHING MATH IN PRISONS continued from cover Amherst. The competition is annual, and it is helpful for stu- DEPARTMENT HEAD’S MESSAGE dents in our department to apply our diverse training and at the A few months later, after having completed some background I’d like to welcomesame you time to gainour modelingNewsletter experience as the by new tackling Department real-life prob Head.- checks I officially and training started sessions ason well21 Januaryas having my syllabus ap- 2018. It’s a true honorlems. We – andlearn somewhat and develop dauntingmathematical – andto follow computational in the footstepsproved by of the Farshid community Hajir college, who awarding the credits to stu- now serves as Vicemethods Provost in classes of Academic and during Affairs our Ph.D. and training, did a but fantastic here we jobdents in parthis 3of years UBB, Ias taught Head. at theI take prison over for the first time. The a department that’sapplied risen these tremendously tools and training in stature in this competition.since I came We to both UMass men in filed 1987. in We’veand came made one-by-one some to introduce themselves. exceptional hires feeland we improved learned a lot our from graduate the real-life and data undergraduate and real-life prob programs.- That’s Ourwhen itgraduates hit me that have I was gone alone onin a room with crimi- to do outstandinglems.” things. Each We’re hopes veryto pursue proud a career of our in mathematical alumni. sciences nals. Obviously, I knew this would be the case, but I hadn’t fully in industry. appreciated that fact. For a few minutes, I was literally speech- A particular area of growth is our number of undergraduate majors, whichless: I was continually unable to greet exceeds my students, expectations. `hi’ was too More complicated and more of Wang explains that dozens of teams entered the first phase of of a word to utter. They finally all sat down and looked up at our incoming studentsthe competition recognize last theOctober. benefits She and of Jinmajoring used advanced in math. ma- meWe expectantly.have almost I finally 1000 calmedmajors down: in 7 I areas:knew thatActuarial excited andScience, Applied Math, Computing,chine learning Pure approaches Math, suchStatistics, as Random Teaching Forest, and Bagging, an Individual nervous look, concentration. it was the same Mathematics one students would is also give an me essential at st part of any 21 centuryAdaboost education, and XGBoost as overto build 15,000 variant UMass models. students Then they take the our beginning classes of each every year. semester. These men were my students. combined several models using ensemble learning methods Any other part of their identity was irrelevant in that moment. Thanks to the hardsuch aswork stacking of our to getsearch better committee,prediction performance. our tenure track positionWith the inweight Math of this Biology realization was sinking filled in, by I was our able top to startcandidate: Assistant Professor Brian Van Koten is an expert in applied probabilityteaching. and numerical analysis, performing computer simulations of molecularBased on the systems resulting with predictive applications models, they in biology,found a few chemistry im- and materials science. We also had a very successful year in hiring 8 newportant outstanding factors such asVisiting driver’s safetyAssistant rating, Professors: the claim’s estimat Siddhant- My firstAgrawal semester, Panagiota went better Birmpathan I could, Noriyuki have ever expected.Hamada , ed payout and vehicle price had a large influence on the likeli- The course was basically an introduction to discrete mathe- Kuan-Wen Lai, Jonathanhood that a Simoneclaim was, fraudulent. Zahra Sinaei The company’s, Zheni Uticdata scientists and Jiayu matics, Zhai a. topicOur whichnew Marshallis particularly Stone appealing VAP, Laura for students Colmenarejo Hernando, will joinsaid theyus in gained Spring new 2019. business insights from Jin and Wang’s new who might dislike — and sometimes even fear — mathematics “models of models.” because of courses they have previously taken. With discrete Our Newsletter, and the on-line Faculty News Briefs at www.math.umass.edu,math, we can provide talk about an love,opportunity solve fun puzzles, to highlight do magic, some be- of the outstanding workMathematics of our and faculty statistics in pushingdepartment the head envelope Nathaniel of Whita knowledge- come inbetter mathematics poker players, and optimize statistics our liveseach in year: many Assistantways Professor Nestor kerGuillen says of thespoke team’s at accomplishment, the Austin workshop “The department “Gerrymandering is very and so Steals much more.Elections: Most students Learn howwere atIt’s first Done surprised and Howthat to Stop It,” and was partproud of of aJie panel and Tangxinon the topicin winning including this competition. US Representative This these Jim things McGovern all related tothis math, year; but Associate very quickly, Professor they start -Paul highlights their talent and training. They have a broad range of ed seeing every aspect of their lives more mathematically. My Hacking was invited to lecture at the 2018 International Congress of Mathematicians; Associate Professor Alexei Oblomkov was expertise which will serve them well in the future.” students had such a fierce passion and thirst for learning the awarded a Simons Fellowship; Professors Markos Katsoulakis and Lucmaterial. Rey-Bellet The continuous received streama major of Airquestions Force during grant classes to develop performance guaranteesProfessors in Markos predictive Katsoulakis modeling; and Luc Professor Rey-Bellet Andrea say that Nahmod was a testament was part to their of a refusal feature to behonoring satisfied womenby mere knowlin the- Notices of the AMS; and Universitythey are very Distinguished proud of their Ph.D. Professor students’ Panos accomplishment, Kevrekidis edge published and to their 4 papers incomparable in the commitmentNature family to achieve of journals. true but, Katsoulakis adds, “I am not really that surprised. Jie and understanding. Our Department Tangxinhosted have3 conferences mustered a wide-rangingthis past year: expertise Associate combining Professor Anna Liu was among the organizers of the 32nd New England Statisticalapplied Symposium mathematics, bringing statistics together and computing nearly 250 that statisticians allowed I won’t to discuss lie: that emergingfirst semester issues — andin Aprilevery subsequent2018; Professor time Andrea Nahmodthem helped to be organize at the same Women time creative in Partial and practical, Differential ultimately Equations I have intaught March in a 2018;prison —and brought Associate its lot Professorof challenges Hongkun too. bringing them in at the top of the competition. The size of the board available would make any mathematician Zhang co-organized Mathematical Physics Perspective of Billards and Dominoes celebrating the 70th birthdays of Pavel Bleher and want to cry. The disparity in the students’ previous knowledge Leonid BunimovichThis in showcases September the training2017. of our applied mathematics stu- was much greater than in the most uneven freshman calculus dents, but specifically demonstrates the strong potential of Jie class — some hadn’t taken a math class in several decades while UMass Amherst undergraduatesand Tangxin in any futureJonah career Chaban paths, they Artem may choose.”Vysogorets, andothers Jimmy had finished Hwang their worked GED while as a in team, prison. led Many by Assistantneeded Professor Matthew Dobson, to produce the top-scoring project amongto 7be competing taught how to teams study. atThe the classroom first ever was Studentloud: there Competition was Using Modeling (SCUDEM)Asked how difficult in Fall was 2017. the competition, Three moreboth SCUDEMstudents said teamsthe a rock led bandby Dobson practicing also in the did next very room, well though in Spring my own 2018 stu-, receiving meritoriousexperience mention was indeed and outstandingdifficult but also mention. fun. The one stressful dents would sometimes give them a run for their money when element, they note, is that they could see their team’s ranking arguing about how to solve some problem. I couldn’t hold office against the other 71 teams each week, and it became increasingly hours and the students couldn’t email me to ask me for help. We are very sad tohard have to stay lost on an top. important In addition tomember the trophy, of the our first faculty, place team Richard Most studentsS. Ellis had, who full-time passed jobs away at the prisonin July and 2018. no quiet Richard place joined the department inmembers 1975, andeach broughtalso taught home certificatesclasses in and Judaism a mini-drone. and the Torahto study as anthe adjunctrest of the professortime. The prisonof Judaic was far and away Near and IEastern had Studies. He was an internationally regarded expert in probability and large deviation theory, who also cared very much about the well-being of his students and colleagues, organizing sessions to relieve stress both inside and outside of the classroom. Richard will be truly missed. 2018-19 Volume 34 13 We are also sorry to report the retirement of two important members of our faculty, Michael Lavine and Bill Meeks, in May 2018. Professor Lavine, a well-respected Bayesian statistician and a leader in our statistics group, had been a department member since 2008. Professor Meeks held the prestigious George David Birkhoff chair since joining the department in 1986; he is a world-renowned differential geometer and topologist, with a distinguished reputation in the area of minimal surfaces.
The support of our alumni and friends is invaluable to us. We want to know how you are doing. Please send us your news, or stop in for a visit.
– Nathaniel Whitaker
DEPARTMENT OF MATHEMATICS & STATISTICS 2018 Volume 33 3
3
to rely on carpools and buses that would tally up a commute of meet the instructor requirements set by the institute granting the three hours in total. Classes were three hours long and in the credits for the course. Many programs also offer non-credited evening, which was challenging for the students and me. I also classes to prepare the students for the credited courses; those had to deal with a few correctional officers who thought inmates NEWpreparatory CHALLENGE classes can often be taught PROBLEMS by grad students. MATHEMATICSdid not deserve to have this chance & and refused to treat them like students. But all of this was amply made up by how enthu- HereUnfortunately, is a selection not every of prison some and of jail the has morea program challenging like UBB STATISTICSsiast, dedicated and grateful my students were. problemsand PUP — thisfrom is the the case 2018 of the Jacob-Cohen-Killam local jails near me. As I arrived prize exam.to start myThree tenure-track additional position prizeat UMass, exam I still problems wanted to keep are NEWSLETTERThat first course proved to be very effective in making students includedteaching math in tothe inmates, Awards but there Dinner was no article such program on page nearby. 14. .. care about math: my students asked me if I could come back the ...... A few college classes in different fields had been taught over the next semester to teach them again even though the class they years, but nothing with much direction and never any classes in EDITEDhad just completed BY was the only math class required for the as- Problemmath. It took 1many. Compute months of emailingthe volume with the of administration the 2018– sociate degree they were completing. I suggested a traditional dimensionalat the Hampshire simplex County Jail before they agreed to even meet Richard S. Ellisroute: calculus Robert or linear algebra.Kusner They requested that I teach with me: they were dubious that any of their men would be inter- 2018 them an introduction to proofs instead — I had occasionally {(estedt1, ...in taking, t2018 college-levelR math.t1 t2018 . shown them some proofs during the semester, and they wanted ...... DESIGNEDmore. Given that BY the community college that was granting the I eventually convinced)∈ them : 0 to ≤ let me ≤ run ··· a≤ Math Circle ≤ 1}with bi- students credits did not offer such a class, we settled on a lecture weekly meetings where we would focus on the process of doing Problem 2. Given numbers a1, a2, a3, a4, suppose Brigetteseries that McKenna would be offered just for fun. Let me emphasize this: amathematics, is defined of solvingrecursively mathematical as problems and exploring inmates took advanced math just for fun. My first students pub- mathematicsn together instead of learning set rules. This would licized the series so much, that it was standing-room only. It was be aa way = of ( agauging + a students’ + a interest + a for)/4. a potential course. The amazing. After that class, we went back to a more traditional Mathn Circle n−1was a success.n−2 Then−3 studentsn−4 would talk about it for IN COOPERATIONmathematical route WITH since many of them now wanted to get a days after our meetings, and the number of students wanting
bachelors of sciences — even Ph.D.’s in some cases — instead Showto attend that increased the sequence steadily throughout {an} converges the semester. and This con- Q.Y. CHEN P.of FLAHERTYassociate degrees, some O.of them GWILLIAM in mathematics. A few of my vinced the administration that it would make sense to offer a calculate L = limn→∞ an...... P. HACKING J.first HOROWITZ students have now beenS. released HROBAR and are now on their way college-level class the next semester. to achieve their dreams. V. LYZINSKI I. MIRKOVIC A. MORALES ProblemI was thrilled, 3. but Consider I was also nervousa regular about tetrahedron how I could raisewith F. PEDIT A.The RAYMOND next semester, I wentC. to RUSSELL MSRI for the Geometric and edgesfunds toof pay length for the 1. credits What the is students the length would of obtain, the shortest some- N. WANG N.Topological WHITAKER Combinatorics program.R. YOUNG My experience with UBB loopthing onthat its organizations surface which like UBB surrounds or PUP usually two vertices?take care ...... The Department of MathematicsIt took and many Statistics months publishes of emailing with Problemthe administration 4. How many at 3×3 the arrays Hampshire are there such its annual newsletter forCounty alumni Jailand before friends. they You agreedare to even meetthat (i) withentries me: include they all were the digits dubious from that1 through important, and we want to hear fromany you! of Please their contact men would us at be interested9, and in (ii) taking entries college-level in every row and math. column are in [email protected] to share your news, let us know how increasing order? you are doing, and learn ways to become involved with the Department. Our websitehad is been a valuable so positive resource that I wanted for to currentfind a way to keep teaching of. One option would have been to go through The Second inmates. I found out there was a program similar to UBB called Chance Pell program, program of the U.S. Department of Ed- Problem 5. .Let En be the coefficients in the happenings and news, so wethe encouragePrison University you toProject visit (PUP),us regularly and I volunteered with ucation that was launched under Obama, that serves 12,000 expansion: .sec x+tan x = ∞ E xⁿ. ⁿ n=0 nn! at www. math.umass.eduthem at the San Quentin State Prison. There are many such inmates a year nationally. Otherwise, there is a ban on fed- programs around the country that are always looking for more eral financial aid for inmates. If this ban were lifted, about Show that they satisfy E0 =E1 =1 and for n≥1 mathematicians to volunteer: http://prisonstudiesproject.org/ 463,000 prisoners would be eligible for a regular Pell Grant. On a more somber note, we mourn the passing on 2 July lists many of them. For those who would like to volunteer but Information... on how to start new sites can be found here: 2018 of our dear colleague Richard S. Ellis, an internationally who might not have enough time to teach an extra three hours https://experimentalsites.ed.gov/exp/expectations.html. regarded probabilist, anda week, a good most friendprograms to allow many for classes of us to on be co-taught by two or three instructors. Tutoring is also another good option that I was very lucky that I got help in acquiring an easier source of campus and in the community. It’s an immeasurable loss to Problem 6. Let An be the set of all subsets S of our Department. For manyrequires years a smaller Richard time commitment.edited the Itannual can also be a good option {1,funding: 2, ..., my n} departmentsuch that chair,S contains Nathaniel the Whitaker, size |S |was of Salso. Let for peridoctoral students who want to volunteer and who do not very interested in prison education and was able to help me to Newsletter and monthly News Briefs, and I — your current Bn be the set of all S in An which are minimal, i.e., editor — enjoyed working with him on both for much of the if S contains some subset T in An then T = S. Show past decade. As I re-drafted the letter soliciting briefs this that the number bn of elements of the set Bn is the 14 DEPARTMENT OF MATHEMATICS & STATISTICS th September, I realized it was based on Richard’s traditional n Fibonacci number Fn (here F1 = 1 = F2 and after text, passed down from him to me several years ago. Both that Fn = Fn−1 + Fn−2). this Newsletter and the News Briefs have become Department traditions, shaped by each of us who has taken on the role of Problem 7. Evaluate π/2 1 editor, but Richard’s influence looms large. He and I shared many common interests outside mathematics, particularly an intellectual curiosity about languages and literature, and both Send solutions, comments, or feedback via email of us have been deeply committed to carry on the tradition of to Professor Franz Pedit
2 get UMass to lift the tuition fees for our students. My chair had inside-out classes is offered by the Inside-Out Center at Temple DEPARTMENTnever had HEAD’Sthe opportunity to MESSAGE teach inmates before, so we decid- University; more information can be found at: https://www.in- ed to co-teach the class together. It was a great experience for all sideoutcenter.org/training.html. I’d like to welcomeinvolved. you to our Newsletter as the new Department Head. I officially started on 21 January 2018. It’s a true honor – and somewhat daunting – to follow in the footstepsSo why do of all Farshid of this? I Hajirbelieve, thatwho offering college-level math now serves as ViceBeing Provost at a small of Academiclocal jail instead Affairs of at a bigand prison did botha fantastic has ad- jobcourses in his in our3 years prisons as is Head.more importantI take over than offering any oth- a department that’svantages risen and tremendously disadvantages. inLet’s stature start with since the negatives. I came toSmall UMass er subject. in 1987. According We’ve tomade Community some College Students Face a exceptional hires jailsand are improved less likely ourto have graduate a higher andeducation undergraduate program, which programs. Very Long Our Road graduates to Graduation have by gone Ginia on Bellafante, among the to do outstandingresults things. in moreWe’re fundraising very proud work of for our those alumni. who volunteer. In- general population, about 40 percent of students who start at a mates stay in general in small jails for a shorter amount of time 2-year college never finish because they do not complete the one A particular area of growth is our number of undergraduate majors, which continually exceeds expectations. More and more of our incoming studentsUBB recognize is an engine the benefits of change of majoring chugging in math. withinWe have thealmost junkyard. 1000 majors It isin impossible7 areas: Actuarial to Science, Applied Math, Computing,overstate Pure the Math, shift Statistics, in thinking Teaching that and takes an Individual place inconcentration. a prisoner’s Mathematics mind once is also he anhas essential part of any 21st century education, as over 15,000 UMass students take our classes each year. been enriched with the potential found in higher learning. A real future has Thanks to the hard work of becomeour search conceivable,committee, our tenureinstead track of positionjust a dreamin Math forBiology someone was filled else. by our top candidate: Assistant Professor Brian Van Koten is an expert in applied probability and numerical analysis, performing computer simulations of molecularand might systems be spending with a lot applications of their time inin biology,and out of chemistry legal math and class materials they have to science. take. Math We is thealso roadblock had a verystopping successful so year in hiring 8 newproceedings. outstanding So class Visiting sizes might Assistant be quite small Professors: — small enough Siddhant many Agrawal people in ,America Panagiota from gettingBirmpa a degree., Noriyuki By teaching Hamada that , Kuan-Wen Lai, Jonathanthat you might Simone wonder, Zahra whether Sinaei this is ,worth Zheni the Utic effort and — beJiayu- class Zhai in prison,. Our it new gives Marshall students a betterStone chance VAP, ofLaura completing Colmenarejo Hernando, will joincause us not in only Spring are there 2019. less inmates to begin with, but also few an associate degree either while in prison or after their release. can commit to a full semester of classes. It is even more unlikely Our Newsletter, andthat thethey on-linewill be there Faculty long enough News to Briefs complete at www.math.umass.edu,enough classes Moreover, theprovide impact an on opportunitythe students’ lives to ishighlight huge. In the some US, of while in prison to earn an associate degree (that is, if sufficiently 70% of prisoners return to prison within three years. The sin- the outstanding work of our faculty in pushing the envelope of knowledge in mathematics and statistics each year: Assistant many classes are offered to do so). gle most effective way to reduce recidivism is education: inmates Professor Nestor Guillen spoke at the Austin workshop “Gerrymanderingthat participate Steals Elections: in any correctional Learn how education It’s Done programs and Howare to Stop It,” and was partOn the of flip a panel side, this on meansthe topic you can including spend more US time Representative with each 43% lessJim likely McGovern to recidivate this than year; those Associate who do not Professor according Paul Hacking was invitedstudent to andlecture help atthem the at 2018 a critical International time of their Congressrelease when of Mathematicians;to: https://www.rand.org/pubs/research_reports/RR266.html Associate Professor Alexei Oblomkov and was awarded a Simonsthey Fellowship; need support Professors to transition Markos to your own Katsoulakis institution or andsome Lucearning Rey-Bellet an associate received or bachelor a major degree Air while Force in prison grant drops to develop performance guaranteesother local in university predictive or community modeling; college. Professor The fact Andrea that you Nahmod the rate of was recidivism part of to a13.7% feature and 5.6%honoring respectively. women Moreover, in the Notices of the AMS; and Universityonly teach a fewDistinguished students also makes Professor it more Panos likely that Kevrekidis you can given published that more 4 thanpapers 70% inof statethe prisonersNature familyhave not of completed journals. convince your institution to lift tuition fees. The small number of high school, it is clear that our social support systems, including students also makes such classes good candidates for inside-out our educational system, have failed so many of these men and nd Our Department classes:hosted classes 3 conferences where half of this the paststudents year: are inmates, Associate and theProfessor women. Anna Offering Liu access was toamong higher educationthe organizers in prisons of is theone way32 New England Statisticalother Symposium half are students bringing from yourtogether institution. nearly For 250 the latter, statisticians this to attemptto discuss to break emerging the cycle ofissues crime in and April poverty 2018; that so Professor many Andrea Nahmodoffers helped the organizeopportunity Women to meet peoplein Partial very different Differential from them Equations- inmates in are March stuck in. 2018; and Associate Professor Hongkun Zhang co-organizedselves Mathematical and change the way Physics they view Perspective the world inof general Billards as well and Dominoes celebrating the 70th birthdays of Pavel Bleher and Leonid Bunimovichas their in Septembereducation. After 2017. observing how much work the inmates In the words of UBB student Steve B., “UBB is an engine of put towards their classes, many are inspired to follow their change chugging within the junkyard. It is impossible to over- UMass Amherst undergraduatesexample to make the Jonah most ofChaban their college, Artem experience, Vysogorets which , andstate Jimmythe shift Hwangin thinking worked that takes as aplace team, in a ledprisoner’s by Assistant mind Professor Matthewthey Dobson also come, to to produceregard as anthe amazing top-scoring opportunity. project For amongthe once 7 competinghe has been enriched teams atwith the the first potential ever foundStudent in higher Competition inmates, an inside-out class offers them a boost in confidence. learning. A real future has become conceivable, instead of just Using Modeling (SCUDEM)They get to see in that Fall they 2017. truly areThree college studentsmore SCUDEM — in classes teams a dream led by for Dobson someone else.”also did very well in Spring 2018, receiving meritoriouswithout mention outside students, and outstanding the inmates oftenmention. falsely believe that the classes are diluted because they are not good enough — and If you treat inmates like students, they will become students We are very sad towhat have is more, lost thatan important they are successful member college of students. our faculty, Another Richard — and S. often Ellis they, who will passed surprise awayyou and in evenJuly become 2018. scholars.Richard joined the department inadvantage 1975, and of inside-out also taught classes classes is that your in Judaism institution and might the ac- TorahThey as will an becomeadjunct inspiring professor agents of of Judaic change andwho Nearwe want Eastern to Studies. He was ancept internationally to count them as partregarded of your teachingexpert induties. probability Training for and seelarge out deviationin our society. theory, who also cared very much about the well-being of his students and colleagues, organizing sessions to relieve stress both inside and outside of the classroom. Richard will be truly missed. 2018-19 Volume 34 15 We are also sorry to report the retirement of two important members of our faculty, Michael Lavine and Bill Meeks, in May 2018. Professor Lavine, a well-respected Bayesian statistician and a leader in our statistics group, had been a department member since 2008. Professor Meeks held the prestigious George David Birkhoff chair since joining the department in 1986; he is a world-renowned differential geometer and topologist, with a distinguished reputation in the area of minimal surfaces.
The support of our alumni and friends is invaluable to us. We want to know how you are doing. Please send us your news, or stop in for a visit.
– Nathaniel Whitaker
DEPARTMENT OF MATHEMATICS & STATISTICS 2018 Volume 33 3
3
SOLUTIONS TO THE 2018 CHALLENGE PROBLEMS
NEW CHALLENGE PROBLEMS Problem 1. What is the volume of the 2018-dimensional simplex MATHEMATICS & Here is a selection of some of the more challenging (t ,...,t ) R2018 ;0 t t 1 ? STATISTICS { 1 2018 ∈ problems≤ 1 ≤···≤ from2018 the≤ 2018} Jacob-Cohen-Killam prize exam. Three additional prize exam problems are NEWSLETTER included1 in the Awards Dinner article on page 14... Solution. The n-volume of the n-simplex equals n! . One way to see this: slice with planes tn = t into (n 1)-simplices rescaled by t,...... integrate on 0 t 1 to get the n-volume of{ the n}-simplex− is 1 times the (n 1)-volume of the (n 1)-simplex,≤ ≤ and apply (reverse) EDITED BY n . Compute the volume of the 2018– induction in n. But perhaps the− most directProblem way is to 1− subdivide the n-cube, whose n- dimensional simplex Richard S. Ellis volume Robert is 1, into Kusnern! congruent n-simplices by permuting the n coordinates. (If you object that they overlap slightly, replace them with open n-simplices,2018 where the the inequalities {(t1, ... , t2018 R t1 t2018 . are strict: these are disjoint and have the same...... n-volume as the (closed) n-simplices.)
DESIGNED BY )∈ : 0 ≤ ≤ ··· ≤ ≤ 1} Given numbers a , a , a , a , suppose Brigette McKenna Problem 2. 1 2 3 4 2. Given numbers a1,a2,a3,a4 suppose an is definedan is defined recursively recursively as as an =(an 1 + an 2 + an 3 + an 4)/4 − − − − an = (an−1 + an−2 + an−3 + an−4)/4. Show that the sequence an converges and calculate L = limn an. IN COOPERATION WITH { } →∞ Solution. More generally, we can start with k numbers a1,a2, ..., ak and define the sequence Show that the sequence {an} converges and Q.Y. CHEN P. FLAHERTYusing averages O.an GWILLIAM=(an 1 + a n 2 + + an calculatek)/k. The L = key lim willa be. ... to...... consider groups of k consecutive terms a ,− ..., a − rather··· than− just one term atn→∞ a time.n P. HACKING J. HOROWITZ S. HROBARn n +k 1 − V. LYZINSKI We will manage to calculate the limit based on an abstract reasoning that will show that I. MIRKOVIC A. MORALES Consider a regular tetrahedron with the limit exists. Let Mn and mn be the maximumProblem and minimum 3. of numbers an, ..., an+k 1. F. PEDIT A. RAYMOND C. RUSSELL − Notice that an+k is between mn and Mn, henceedges the of same length is true 1. What for all isa then+1 ,length ..., an+ kof. Thisthe shortest N. WANG N. WHITAKER R. YOUNG implies that the sequence Mn is decreasingloop and onmn itsis surface increasing. which So surrounds they converge two vertices? to .. numbers M m. ≥ ...... The Department of MathematicsTaking and averages Statistics gets publishes numbers closer together and this can be used to show that M m Problem 4. How many 3×3 arrays aren − theren such its annual newsletter for alumnigoes to and zero. friends. Hence, Youm = areM and then the sequencethat (i) entriesan converges include to all the the limit digitsL =fromm. 1 through important, and we want to hear Oncefrom you! we know Please lim contactan = L uswe at will see that L has9, and to be(ii) (a entries1+2a2+ in every+ka krow)/(1+2+ and column+k). are in [email protected] to share your news, let us know how ··· ··· k The reason is that the following weighted averageincreasingAn =[ order?an+2a n +1+ +kan+k 1]/( 1 i) you are doing, and learn ways ofto thebecomenth group involved does with not the change with n : ··· − Department. Our website is a valuable resourcek for current Problem 5. .Let E be the coefficients in the happenings and news, so we encourage(An youAn to+1 visit)( us iregularly)= (an +2an+1 + + kan+k 1) (an+1 +2n an+2 + + kan+k) − ··· − − ∞ ···xⁿ n nn! at www. math.umass.edu 1 expansion: .sec x+tan x = E . ⁿ =0 =(an + an+1 + + an+Showk 1) thatkan they+k =0 satisfy. E =E =1 and for n≥1 ··· − − 0 1 Now A = lim A =(L +2L + + kL)/(1 + + k)=L. On a more somber note, we mourn 1the passingn on 2 July ··· ...··· 2018 of our dear colleague Richard S. Ellis, an internationally regarded probabilist, and a good friend to many of us on campus and in the community. It’s an immeasurable loss to Problem 6. Let An be the set of all subsets S of our Department. For many years Richard edited the annual {1, 2, ..., n} such that S contains the size |S| of S. Let
Newsletter and monthly News Briefs, and I — your current Bn be the set of all S in An which are minimal, i.e., editor — enjoyed working with him on both for much of the if S contains some subset T in An then T = S. Show past decade. As I re-drafted the letter soliciting briefs this that the number bn of elements of the set Bn is the 16 DEPARTMENT OF MATHEMATICS & STATISTICS th September, I realized it was based on Richard’s traditional n Fibonacci number Fn (here F1 = 1 = F2 and after text, passed down from him to me several years ago. Both that Fn = Fn−1 + Fn−2). this Newsletter and the News Briefs have become Department traditions, shaped by each of us who has taken on the role of Problem 7. Evaluate π/2 1 editor, but Richard’s influence looms large. He and I shared many common interests outside mathematics, particularly an intellectual curiosity about languages and literature, and both Send solutions, comments, or feedback via email of us have been deeply committed to carry on the tradition of to Professor Franz Pedit
2 DEPARTMENT HEAD’S MESSAGE I’d like to welcome you3. toConsider our Newsletter a regular as tetrahedronthe new Department with edges Head. of length I officially 1. What started is the lengthon 21 January of the shortest 2018. It’s a true honorloop – and on somewhat its surface daunting which surrounds – to follow two vertices?in the footsteps of Farshid Hajir, who now serves as Vice ProvostSolution. of AcademicBy a “loop Affairs on its and surface did a whichfantastic surrounds job in his two 3 years vertices” as Head. we mean:I take theover loop has a department that’s risenno tremendously self-intersections, in stature one component since I came of to its UMass complement in 1987. on We’ve the surface made some contains two (say, exceptional hires and improvedA and B) our of thegraduate tetrahedron’s and undergraduate four vertices, programs. and another Our graduates component have of gone the complement on to do outstanding things.contains We’re thevery other proud two of verticesour alumni. (C and D). With this clarification, we argue that shortest such loop has length 2. First observe that there is such a loop with length exactly 2, A particular area of growthnamely, is our any number of the rectangularof undergraduate loops majors, on the surfacewhich continually lying in planes exceeds parallel expectations. to the edges More and more of our incoming studentsAB recognizeand CD the. benefits But any of other majoring such in loop math. which We meandershave almost back 1000 and majors forth in among7 areas: theseActuarial Science, Applied Math, Computing,rectangular Pure Math, loops Statistics, would be Teaching longer. Toand see an this,Individual cut the concentration. tetrahedron alongMathematics the edges is alsoAB an essential part of any 21st centuryand education,CD, as as well over as 15,000 along one UMass more students edge, say takeAC our: the classes result each unfolds year. into a parallelogram in the plane, each of the rectangular loops unfold to a straight segment of length 2, and the Thanks to the hard workmeandering of our search loop committee, unfolds to aour longer tenure curve. track (Thisposition is ain simple Math exampleBiology was of afilled “calibration” by our top candidate: Assistant Professor Brianargument.) Van Koten is an expert in applied probability and numerical analysis, performing computer simulations of molecular systems with applications in biology, chemistry and materials science. We also had a very successful year in hiring 8 new outstanding Visiting Assistant Professors: Siddhant Agrawal, Panagiota Birmpa, Noriyuki Hamada, Kuan-Wen Lai, Jonathan Simone, Zahra Sinaei, Zheni Utic and Jiayu Zhai. Our new Marshall Stone VAP, Laura Colmenarejo Hernando, will join us4. inConsider Spring 2019. all 3 3 arrays such that (i) entries include all the digits from 1 through 9, and (ii) × entries in every row and column are in increasing order. How many such arrays are there? Our Newsletter, and the on-line Faculty News Briefs at www.math.umass.edu, provide an opportunity to highlight some of Solution. Think of such array as a matrix a with entries (a ), with 1 i, j 3. Clearly, the outstanding work of our faculty in pushing the envelope of knowledge in mathematicsij and≤ statistics≤ each year: Assistant Professor Nestor Guillena11 spoke= 1 and at thea33 Austin= 9. Also,workshop when “Gerrymandering we remove the mainSteals diagonal, Elections: what Learn remains how It’s areDone two and How to “hooks” A (upper right corner) and B (left lower corner), each of length 3. Notice that Stop It,” and was part of a panel on the topic including US Representative Jim McGovern this year; Associate Professor Paul a 4, 5, 6 , so we distinguish three cases: Hacking was invited to 22lecture∈{ at the} 2018 International Congress of Mathematicians; Associate Professor Alexei Oblomkov was awarded a Simons Fellowship;Case a22 Professors= 4. Observe Markos that Katsoulakis the array aandis determinedLuc Rey-Bellet once received we know a major the three Air Force numbers grant to develop a ,a ,a 2, 3, ..., 8 in the hook A. First, since hooks are linearly ordered there is performance guarantees{ 12in predictive13 23}⊆{ modeling;} Professor Andrea Nahmod was part of a feature honoring women in the Notices of the AMS; and Universityonly oneDistinguished way to position Professor given Panos three Kevrekidis numbers inpublished one of the4 papers hooks inA theor NatureB. Second, family the of journals. numbers in B are determined by those in A as the three remaining numbers in 2, 3, ..., 8 . { } So, we only need to count all possible choices choices of a ,a ,a . nd Our Department hosted 3 conferences this past year: Associate Professor Anna{ Liu12 was13 among23} the organizers of the 32 New England Statistical SymposiumNotice that bringing in positions together 12 nearly and 21 250 we statisticians can only use to 2 discuss and 3. emerging Finally, once issues we in choose April a2018;12 as Professor Andrea Nahmod helpedone organize of these Women two numbers in Partial the setDifferentiala13,a23 Equationscan be any in March pair from 2018; the and remaining Associate 4 numbersProfessor Hongkun { } Zhang co-organized Mathematical4, 5, 6, 7. Thus, Physics there Perspective are 2 ( 4 ) =of Billards 12 possibilities and Dominoes in this celebrating case. the 70th birthdays of Pavel Bleher and · 2 Leonid Bunimovich in September 2017. Case a22 = 6 is symmetric so it remains to consider the Case a22 = 5. Here, the hook A can be any triple from the set 2, 3, 4, 6, 7, 8 with the exception of 2, 3, 4 and 6, 7, 8 . 6 { } { } { } UMass Amherst undergraduatesThus, there Jonah are ( Chaban3 ) 2 =, Artem 18 possibilities. Vysogorets, and Jimmy Hwang worked as a team, led by Assistant Professor Matthew Dobson, to produce the− top-scoring project among 7 competing teams at the first ever Student Competition In conclusion, there are 12 2 + 18 = 42 such arrays. Using Modeling (SCUDEM) in Fall 2017. Three · more SCUDEM teams led by Dobson also did very well in Spring 2018, receiving meritorious mentionNote. This and problem outstanding is a very mention. particular case of the Hook length formula for the number of Young tableaux of hook shape. Young tableaux are basic objects of combinatorics related We are very sad to haveto lost representation an important theory member and of one our can faculty, (carefully) Richard extend S. Ellis the, who above passed reasoning away toin proveJuly 2018. this Richard joined the department in 1975,formula. and also taught classes in Judaism and the Torah as an adjunct professor of Judaic and Near Eastern Studies. He was an internationally regarded expert in probability and large deviation theory, who also cared very much about the well-being of his students and colleagues, organizing sessions to relieve stress both inside and outside of the classroom. Richard will be truly missed. 2018-19 Volume 34 17 We are also sorry to report the retirement of two important members of our faculty, Michael Lavine and Bill Meeks, in May 2018. Professor Lavine, a well-respected Bayesian statistician and a leader in our statistics group, had been a department member since 2008. Professor Meeks held the prestigious George David Birkhoff chair since joining the department in 1986; he is a world-renowned differential geometer and topologist, with a distinguished reputation in the area of minimal surfaces.
The support of our alumni and friends is invaluable to us. We want to know how you are doing. Please send us your news, or stop in for a visit.
– Nathaniel Whitaker
DEPARTMENT OF MATHEMATICS & STATISTICS 2018 Volume 33 3
3
SOLUTIONS TO THE 2018 CHALLENGE PROBLEMS continued from p. 17
NEW CHALLENGE PROBLEMS xn 5. Show that the coefficients E in the expansion of f(x) = sec x + tan x as ∞ E . satisfy MATHEMATICS & n Here is a selection of some ofn=0 then moren! challenging E0 = E1 = 1 and for n 1 ≥ n problems from the 2018 Jacob-Cohen-Killam prize STATISTICS n 2En+1 = ( k )EkEn k. exam. Three− additional prize exam problems are NEWSLETTER k=0 included in the Awards Dinner article on page 14... Solution. The two sides in the required identity...... are coefficients of xn in expansions of 2 2 EDITED2f BYand f . So, the identity for n>0 will follow from 2f = f + 1. First notice that 2 Problem2 1. Compute the volume of the2 2018– 1/f = sec(x) tan(x), since sec (x) tan(x) = 1. Then f = sec(x) tan(x) + sec(x) = − − dimensional2 simplex Richard S. Ellis sec( xRobert)f. So, indeed Kusner 2f = 2 sec(x)f =(f +1 /f)f = f + 1. Also, E0 = f(0) = 1 and 1 2 2018 E1 = f (0) = 2 [f(0) + 1] = 1. {(t1, ... , t2018 R t1 t2018 .
Note. These numbers E form the sequence 1,...... 1, 2, 5, 16, 61,... . They are called the Euler n DESIGNEDnumbers BY(see Wikipedia). They appear in discrete mathematics)∈ and : 0 ≤ count ≤the ··· ≤ number ≤ of 1} permutations of 2n elements that are alternatingProblem(go up 2. and Given down, numbers up and down,...),a1, a2, a3, a For4, suppose Brigette McKenna a is defined recursively as instance for n = 2 we have two such: 1324 andn 2314.
6. Let be the set of all subsets S of 1, 2, ..., n asuch = ( thata +S acontains + a the + sizea )/4.S of S. Let An { } n n−1 n−2 n−3 n−4 | | IN COOPERATIONn be the WITH set of all S in n which are minimal , i.e., the only T in n that S contains is S B S th S itself. Show that the number bn of elements of theShow set thatn is the nsequenceFibonacci {a } number convergesFn where and B n Q.Y. CHEN P. FLAHERTYF1 =1= F2 andO. after GWILLIAM that Fn = Fn 1 + Fn 2. − − calculate L = limn→∞ an...... P. HACKING J. HOROWITZSolution. The partS. HROBAR of n consisting of all S n that do not contain n is n 1. The B ∈B B − V. LYZINSKI I. MIRKOVICremainder consistsA. MORALES of all S that contain n. Such S does not contain 1 because R ∈Bn Problem 3. Consider a regular tetrahedron with 1 , so S would not be minimal. So, to S one can associate S obtained from S by F. PEDIT A. RAYMOND{ }∈A n C. RUSSELL edges of length 1. What is the length of the shortest removing n and then also S = S 1= x 1; x S . Then S lies in 1, ..., n 2 and N. WANG N. WHITAKER R. YOUNG − { − loop ∈on its} surface which surrounds{ − two} vertices? .. S S gives a bijection of and n 2. So, bn = bn 1 +bn 2 ! Also, clearly b1 =1=b2. → R B − − − ...... 7. Evaluate π/2 1 . The Department of Mathematics and Statistics0 1+(tan publishesx)√2018 Problem 4. How many 3×3 arrays are there such its annual newsletter for alumni and friends. You are √ that (i) entries include allπ/ the2 digits1 from 1 through Solution. Use shorthand α = 2018 and rewrite the integral I = 0 1+(tan x)α dx via important, and we want to hear from you! Please contact us at 9,α and (ii) entries in every row and column are in substitution x = π u as I = π/2 (tan x) dx. Then 2I = π/2 1 dx = π/2. So, [email protected] to share your news, let us 2know− how 0 1+(tan xincreasing)α order? 0 you are doing, and learn waysI to= becomeπ/4 regardless involved of withα ! the Department. Our website is a Note.valuableWe resource managed for tocurrent calculate this definite integral without knowing indefinite in- . .Let E be the coefficients in the happenings and news, so we encouragetegral, becauseyou to visit of us a regularly special property of theProblem function 5 (symmetryn under x = π u). ∞ xⁿ 2 n expansion: .sec x+tan x = Ex2 /2. ⁿ n=0 −n! at www. math.umass.edu The most famous trick of this kind is the calculation of J = ∞ e− dx. Here, 2 (x2+y2)/2 −∞ J = 2 e− dx dy can be easily calculatedShow that by they passing satisfy to polarE =E coordinates=1 and for n≥1 R 0 1 x = r cos(φ),y= r sin(φ), because of the rotational symmetry of the function e (x2+y2)/2. On a more somber note, we mourn the passing on 2 July ... − 2018 of our dear colleague RichardThe S. result Ellis,J an= internationally√2π is essential in probability (normal distribution), and then also in regarded probabilist, and a goodnumber friend theory to many (zeta of function) us on and quantum field theory (Feynman integrals). campus and in the community. It’s an immeasurable loss to Problem 6. Let An be the set of all subsets S of our Department. For many years Richard edited the annual {1, 2, ..., n} such that S contains the size |S| of S. Let
Newsletter and monthly News Briefs, and I — your current Bn be the set of all S in An which are minimal, i.e., editor — enjoyed working with him on both for much of the if S contains some subset T in An then T = S. Show past decade. As I re-drafted the letter soliciting briefs this that the number bn of elements of the set Bn is the 18 DEPARTMENT OF MATHEMATICS & STATISTICS th September, I realized it was based on Richard’s traditional n Fibonacci number Fn (here F1 = 1 = F2 and after text, passed down from him to me several years ago. Both that Fn = Fn−1 + Fn−2). this Newsletter and the News Briefs have become Department traditions, shaped by each of us who has taken on the role of Problem 7. Evaluate π/2 1 editor, but Richard’s influence looms large. He and I shared many common interests outside mathematics, particularly an intellectual curiosity about languages and literature, and both Send solutions, comments, or feedback via email of us have been deeply committed to carry on the tradition of to Professor Franz Pedit
2 ALUMNI PROFILE continued from cover class project, an online blog, or a Shiny app, is the easiest way to get your name out there. DEPARTMENT HEAD’S MESSAGE Q. How do you spend your time in a typical day? I’d like to welcome you to our Newsletter as the new Department Head.Q. As I officially a MA state employee, started I’mon obligated21 January to ask about the Pa- There are large variations based on the day of the week 2018. It’s a true honor – and somewhat daunting – to follow in the footstepstriots. Do of you Farshid think Tom Hajir Brady, who the best quarterback ever or and the week of the year, but it averages out to about 50% in now serves as Vice Provost of Academic Affairs and did a fantastic jobis hein thehis best 3 years professional as Head. athlete I take ever? over R (split into data wrangling, visualization, and modeling), 25% The probability of both of these being true is greater than 0. a department that’stalking risen with tremendously collaborators, and in stature25% on other since projects I came (such to UMassas in 1987. We’ve made some exceptional hires eventand planning,improved presentations, our graduate etc). Theand calendarundergraduate is fairly rigid, programs. Our graduates have gone on to do outstandingin things. that on Monday,We’re very everyone proud cares of aboutour alumni. what happened over the weekend (so we share data-driven reports), but by Thursday, A particular area weof havegrowth all moved is our onto number next week. of undergraduate majors, which continually exceeds expectations. More and more of our incoming students recognize the benefits of majoring in math. We have almost 1000 majors in 7 areas: Actuarial Science, Applied Math, Computing,Q. You have aPure PhD fromMath, Brown Statistics, in Biostatistics, Teaching and and you werean Individual concentration. Mathematics is also an essential part of any 21st centurya tenure education, track professor as atover Skidmore 15,000 College. UMass How students have men take- our classes each year. tors and colleagues reacted to your move to the NFL? I’ve done sports on the side for more than a decade (as an Thanks to the hardexample, work when of ourI was search at UMass committee, and learning ourPoisson tenure regression, track position in Math Biology was filled by our top candidate: Assistant ProfessorI immediately Brian Van started Koten a project is an onexpert NHL penalties),in applied so probabilitynot sure andNew facultynumerical member analysis, performing computer simulations of molecularanyone was systems that surprised. with applicationsAnd I’m lucky enough in biology, to still chemistryteach Mark and Wilson materials science. We also had a very successful year in hiring 8 newone courseoutstanding a year at Visiting Skidmore Assistant as a lecturer. Professors: One big perk Siddhant of Agrawal, Panagiota Birmpa, Noriyuki Hamada, Kuan-Wen Lai, Jonathanworking at theSimone league ,office Zahra (as Sinaei opposed, Zhenito a team) Utic is thatand I Jiayucan Zhai. Our new Marshall Stone VAP, Laura Colmenarejo Hernando, will joinpublish us somein Spring of our 2019.work, and so in that sense, I still hopefully can contribute to the academic community. APPLIED MATH MASTER’S PROJECTS Our Newsletter, andQ. What the on-lineaspects of Faculty your graduate News (and Briefs undergraduate) at www.math.umass.edu, edu- provide an opportunity to highlight some of the outstanding workcation of have our been faculty the most in usefulpushing for yourthe envelopecurrent job? of knowledgeThe inApplied mathematics Math master’s and projects statistics this eachyear year:were overseen Assistant Professor Nestor GuillenIt’s extremely spoke humbling at the Austin to know workshop that no matter “Gerrymandering how many by Qian-Yong Steals Elections: Chen. There Learn were threehow groupIt’s Done projects, and whose How to Stop It,” and was partstatistical of a tools panel I feel on comfortable the topic using,including there’s USalways Representative more to titles Jimand abstractsMcGovern are shown this year; below. Associate The full project Professor reports Paul Hacking was invitedlearn. to Grad lecture school at in the statistics 2018 ensures International you are familiar Congress with aof Mathematicians;can be viewed at: Associate http://www.math.umass.edu/graduate/ Professor Alexei Oblomkov was awarded a Simonsmuch Fellowship; larger framework Professors of options Markos for analyses, Katsoulakis and so the and abil- Lucapplied-ms#projects Rey-Bellet received a major Air Force grant to develop performance guaranteesity to know in whatpredictive tools will modeling; and will not Professor work (or, perhaps,Andrea if Nahmod was part of a feature honoring women in the Notices you need to write a new approach) is the main benefit. Three of the AMS; and University Distinguished Professor Panos Kevrekidis published 4 papers in the Nature family of journals. approaches that I use disproportionately often: multi-level mod- Smart Grid eling, data visualization, bootstrapping. Rachel Aronow, Aaron da Silva, Rose Dennis, George Kevre- nd Our Department hosted 3 conferences this past year: Associate Professorkidis, RichardAnna Liu Touret, was Lance among Wrobel the organizers of the 32 New England StatisticalQ. Symposium What advice bringingdo you have together to our current nearly undergraduate 250 statisticians to discuss emerging issues in April 2018; Professor Andrea Nahmodand helped graduate organize students Women who are interested in Partial in Differentialusing their math Equations- Abstract in March 2018; and Associate Professor Hongkun Zhang co-organizedematical Mathematical and statistical Physics skills in Perspective the field of sports of Billards analytics? and DominoesGlobal depletion celebrating of resources the and70th increased birthdays demand of Pavel on our Bleher and Leonid Bunimovich inThe September neatest aspect 2017. about working in sports is that much of electric grid have resulted in a need for innovation in support the time that I’m at work, it doesn’t really feel like it, as these are of an intelligent utility network the Smart Grid. Thus, the en- questions I’d want to answer regardless of whether or not I am hancement of electrical power interactions for both utilities UMass Amherst undergraduates Jonah Chaban, Artem Vysogorets, and Jimmy Hwang worked as a team, led by Assistant doing it for a job. That said, jobs outside of sports may pay more, and customers has become a major focus for current research. Professor Matthewcome Dobson with a better, to produce work/life thebalance, top-scoring and will allow project for more among At 7a microscalecompeting level, teams we use at gradient the first boosting ever Studentmodels to preCompetition- Using Modeling (SCUDEM)flexibility with in respect Fall 2017. to where Three you live. more The SCUDEM primary waysteams dict led electrical by Dobson power consumption also did very and well solar inpower Spring generation 2018 , receiving meritoriousinto sports mention analytics and are outstanding knowing either mention. R or Python, boasting for a single home. We also develop a dashboard as a visual- enough (pending the role) statistical expertise, and some level ization tool for this analysis. At a macroscale level, we explore We are very sad toof havefamiliarity lost withan important whatever sport member you are lookingof our into.faculty, In that Richard the cost S. optimization Ellis, who ofpassed power dispatchaway in between July 2018. various Richard ener- joined the department insense, 1975, proving and alsoyou fit taught all three classes of these in criteria,Judaism say andthrough the aTorah gy sources as an in adjunct a simplified professor model ofof theJudaic German and electric Near Easterngrid. Studies. He was an internationally regarded expert in probability and large deviation theory, who also cared very much about the well-being of his students and colleagues, organizing sessions to relieve stress both inside and outside of the classroom. Richard will be truly missed. 2018-19 Volume 34 19 We are also sorry to report the retirement of two important members of our faculty, Michael Lavine and Bill Meeks, in May 2018. Professor Lavine, a well-respected Bayesian statistician and a leader in our statistics group, had been a department member since 2008. Professor Meeks held the prestigious George David Birkhoff chair since joining the department in 1986; he is a world-renowned differential geometer and topologist, with a distinguished reputation in the area of minimal surfaces.
The support of our alumni and friends is invaluable to us. We want to know how you are doing. Please send us your news, or stop in for a visit.
– Nathaniel Whitaker
DEPARTMENT OF MATHEMATICS & STATISTICS 2018 Volume 33 3
3
Through these levels of study, we aim to establish a deeper un- to predict growth trends based on the given data. Finally, we derstanding of the potential requirements of a modern Smart examine a treatment model adapted from the competitive Grid. two-equation Lotka-Volterra system and perform a stability NEWanalysis andCHALLENGE obtain numerical results. PROBLEMS MATHEMATICSCancer Growth Modeling & Here is a selection of some of the more challenging STATISTICSMichael Barmann, Ryan Wilson, Nick Malloy, Andrew problems‘Hearing’ the from Clusters the in 2018a Directed Jacob-Cohen-Killam Graph” prize Xiang, Junsang You exam.Chris Brissette,Three additionalMatthew Gagnon, prize exam Brendan problems Shanahan, are James Smith. NEWSLETTERAbstract included in the Awards Dinner article on page 14... In this project, we investigate the dynamics of cancer growth ...... Abstract EDITEDand treatment BY using a combination of statistical, analytical, We examine the. Computegeneralization the of volumea fully-distributed of the 2018– method and numerical approaches. We first review three common Problemfor computing 1 spectral clusters to the case of aperiodic strong- dimensional simplex Richard S. Ellismodels of cancer Robert growth–the Kusner Exponential, Power Law, and ly-connected digraphs. In doing this we show that the sign of Gompertz-Laird models – and then fit these models to tumor {(eigenvectort , ... , t componentsR2018 can be obtainedt via thet Fourier series. volume data collected from laboratory mice. We obtain pa- of a1 local wave-equation2018 relaxation.1 Further we2018 provide a run- ...... rameter estimates and assess how well each model fits the data. time complexity)∈ for this variety: 0 ≤ of digraphs≤ ··· ≤ differing ≤ from1} the DESIGNEDWe also employ BY a Support Vector Regression (SVR) algorithm undirected case Given numbers a , a , a , a , suppose Brigette McKenna Problem 2. 1 2 3 4 an is defined recursively as
an = (an−1 + an−2 + an−3 + an−4)/4. IN COOPERATION WITH
Show that the sequence {an} converges and Q.Y. CHEN P. FLAHERTY O. GWILLIAM calculate L = limn→∞ an...... P. HACKING J. HOROWITZ S. HROBAR
V. LYZINSKI I. MIRKOVIC A. MORALES Problem 3. Consider a regular tetrahedron with F. PEDIT A. RAYMOND C. RUSSELL edges of length 1. What is the length of the shortest N. WANG N. WHITAKER R. YOUNG loop on its surface which surrounds two vertices? ...... The Department of Mathematics and Statistics publishes Problem 4. How many 3×3 arrays are there such its annual newsletter for alumni and friends. You are that (i) entries include all the digits from 1 through important, and we want to hear from you! Please contact us at 9, and (ii) entries in every row and column are in [email protected] to share your news, let us know how increasing order? you are doing, and learn ways to become involved with the Department. Our website is a valuable resource for current happenings and news, so we encourage you to visit us regularly Problem 5. .Let En be the coefficients in the ∞ xⁿ n at www. math.umass.edu expansion: .sec x+tan x = E . ⁿ n=0 n!
Show that they satisfy E0 =E1 =1 and for n≥1 On a more somber note, we mourn the passing on 2 July ... 2018 of our dear colleague Richard S. Ellis, an internationally regarded probabilist, andWork-life a good friend balance! to many Faculty, of us staff on and family members at department campus and in the community. It’s an immeasurable loss to Problem 6. Let An be the set of all subsets S of our Department. For manyChristmas years Richard party edited 2019. the annual {1, 2, ..., n} such that S contains the size |S| of S. Let
Newsletter and monthly News Briefs, and I — your current Bn be the set of all S in An which are minimal, i.e., editor — enjoyed working with him on both for much of the if S contains some subset T in An then T = S. Show past decade. As I re-drafted the letter soliciting briefs this that the number bn of elements of the set Bn is the 20 DEPARTMENT OF MATHEMATICS & STATISTICS th September, I realized it was based on Richard’s traditional n Fibonacci number Fn (here F1 = 1 = F2 and after text, passed down from him to me several years ago. Both that Fn = Fn−1 + Fn−2). this Newsletter and the News Briefs have become Department traditions, shaped by each of us who has taken on the role of Problem 7. Evaluate π/2 1 editor, but Richard’s influence looms large. He and I shared many common interests outside mathematics, particularly an intellectual curiosity about languages and literature, and both Send solutions, comments, or feedback via email of us have been deeply committed to carry on the tradition of to Professor Franz Pedit
2 DEPARTMENT HEAD’S MESSAGE I’d like to welcome youTHE to our BOURBAKI Newsletter SONGas the new Department Head.Note I officiallyto faculty and started graduate students:on 21 January I hope to hear this 2018. It’s a true honor – and somewhat daunting – to follow in the footstepsat parties ofin theFarshid department Hajir in, 2020who — start learning the words now! – Ed. now serves as Vice ProvostThe following, of Academic sung to Affairs the tune and of “Thedid a Battlefantastic Hymn job in his 3 years as Head. I take over of The Republic”, originated (first 2 verses and chorus) a department that’s risen tremendously in stature since I came to UMassHistorical in 1987. note: We’ve Nicholas made Bourbaki some was the pseudonymous at University of Chicago in the 1950s. The later verses group of mostly French mathematicians whose books and exceptional hires and improvedwere written our by Mark graduate Wilson and and undergraduate Joel Robbin at Uni programs.- Our graduates have gone on seminar were very influential in mid-20th century pure to do outstanding things.versity We’re of Wisconsin very proud the 1990s. of our alumni. mathematics — check them out on Wikipedia. A particular area of growth is our number of undergraduate majors, which continually exceeds expectations. More and more of our incoming students recognize the benefits of majoring in math. We have almost 1000 majors in 7 areas: Actuarial Science, Applied Math, Computing, Pure Math, Statistics, Teaching and an Individual concentration. Mathematics is also an essential part of any 21st century education, as overAnalysts, 15,000 topologists, UMass students geometers take agree: our classes each year. When it comes to generality, there’s none like Bourbaki! Thanks to the hard work of our searchOne committee, theorem byour them tenure will trackequal Nposition by you in and Math me, Biology was filled by our top candidate: Assistant Professor Brian Van Koten isBourbaki an expert goes in marching applied probability on! and numerical analysis, performing computer simulations of molecular systems with applications in biology, chemistry and materials science. We also had a very successful year in hiring 8 new outstanding VisitingChorus: Assistant Professors: Siddhant Agrawal, Panagiota Birmpa, Noriyuki Hamada, Kuan-Wen Lai, Jonathan Simone, ZahraGlory, Sinaei glory, hallelujah,Zheni Utic and Jiayu Zhai. Our new Marshall Stone VAP, Laura Colmenarejo Hernando, will join us in Spring 2019.Their generality will fool ya-- They’re axiomatically peculiah! Our Newsletter, and the on-line FacultyBourbaki News Briefs goes marching at www.math.umass.edu, on! provide an opportunity to highlight some of the outstanding work of our faculty in pushing the envelope of knowledge in mathematics and statistics each year: Assistant To prove that two plus two is four, here is what they do: Professor Nestor Guillen spoke at the Austin workshop “Gerrymandering Steals Elections: Learn how It’s Done and How to They show that A plus B is C if A and B are 2; Stop It,” and was part of a panel on the topic including US Representative Jim McGovern this year; Associate Professor Paul We know that C is half of D and D is four times 2, Hacking was invited to lecture at the 2018Bourbaki International goes marching Congress on! of Mathematicians; Associate Professor Alexei Oblomkov was awarded a Simons Fellowship; Professors Markos Katsoulakis and Luc Rey-Bellet received a major Air Force grant to develop performance guarantees in predictive [Chorus]modeling; Professor Andrea Nahmod was part of a feature honoring women in the Notices of the AMS; and University Distinguished Professor Panos Kevrekidis published 4 papers in the Nature family of journals. They commenced to write a book to train young analysts, nd Our Department hosted 3 conferencesbut this in pastfilling year: in foundations, Associate Professor they encountered Anna Liu many was twists. among the organizers of the 32 New England Statistical Symposium bringingThough together their nearly dream 250 to statisticiansend in finite to time discuss has vanishedemerging in issuesthe mists, in April 2018; Professor Andrea Nahmod helped organize WomenBourbaki in Partial goes marching Differential on! Equations in March 2018; and Associate Professor Hongkun Zhang co-organized Mathematical Physics Perspective of Billards and Dominoes celebrating the 70th birthdays of Pavel Bleher and Leonid Bunimovich in September 2017.[Chorus]
UMass Amherst undergraduates JonahIn Chaban the glory, Artemof the twenties Vysogorets came, toand be Jimmy homology: Hwang worked as a team, led by Assistant Professor Matthew Dobson, to producethose the groups top-scoring of Emmy project Noether among which 7 competing transfigured teams you atand the me. first ever Student Competition Using Modeling (SCUDEM) in Fall 2017.As she Three tried tomore make SCUDEM them cyclic, teams Bourbaki led by Dobsonhas made also them did free! very well in Spring 2018, receiving meritorious mention and outstandingBourbaki goes mention. marching on!
We are very sad to have lost an important member of our faculty, Richard S. Ellis, who passed away in July 2018. Richard joined the department in 1975, and also taught classes in Judaism and the Torah as an adjunct professor of Judaic and Near Eastern Studies. He was an internationally regarded expert in probability and large deviation theory, who also cared very much about the well-being of his students and colleagues, organizing sessions to relieve stress both inside and outside of the classroom. Richard will be truly missed. 2018-19 Volume 34 21 We are also sorry to report the retirement of two important members of our faculty, Michael Lavine and Bill Meeks, in May 2018. Professor Lavine, a well-respected Bayesian statistician and a leader in our statistics group, had been a department member since 2008. Professor Meeks held the prestigious George David Birkhoff chair since joining the department in 1986; he is a world-renowned differential geometer and topologist, with a distinguished reputation in the area of minimal surfaces.
The support of our alumni and friends is invaluable to us. We want to know how you are doing. Please send us your news, or stop in for a visit.
– Nathaniel Whitaker
DEPARTMENT OF MATHEMATICS & STATISTICS 2018 Volume 33 3
3
The following alumni and friends have made generous contributions to the Department of Mathematics and Statistics between between July 2018 and December 2019. Your gifts help us improve our programs and enrich the educational experiences of our students. We deeply appreciate your continuing support. NEW CHALLENGE PROBLEMS MATHEMATICSDonald C. Abbott & Mr. Leonard L. DaltonHere & Mrs. is Leonaa selection Mr. of Benjaminsome of David the moreJohnson challenging Dalton Mrs. Christina F. Abel problems from theMrs. 2018 Patricia Jacob-Cohen-Killam S. Jones prize STATISTICS Dr. Ashley M. DaSilva Mr. Nathan W. Adams exam. Three additionalDr. William prize D. Goodhue,exam problems Jr. are NEWSLETTERMiss Geraldine A. Amprimo Mrs. Che Yee Der Mr. Carl J. Britton Jr. & Mrs. Margaret Mr. Henri V. Azibert & Mrs. Susan H. Ms. Anna C. Derby included in the AwardsM. Britton Dinner article on page 14... Azibert Mr. Kyle DeSormier ...... Mr. George A. Morin, Jr. EDITEDMrs. June L. BY Bacon Dr. Michael A. Diehl Problem 1. ComputeMr. Herbert the P.volume Mehlhorn of Jr. the 2018– Dr. John B. Baillieul & Mrs. Patricia P. Mrs. Elizabeth M. Doanedimensional simplexMr. William C. Welsh, Jr. Richard S. EllisBaillieul Robert Kusner Mr. Neil F. Doherty Mr. William H. Cox, Jr. & Mrs. Carol L. Mrs. Joan Barksdale & Mr. Edgar W. Ms. Constance R. Duffy{( , ... , 2018Cox Barksdale, Jr. t1 t2018 R t1 t2018 . Mr. Adam R. Eisner & Ms. Jill M. Eisner Ms. Lisa A. Juris Ms. Amy E. Beresky ...... DESIGNED BY Mr. David J. Ellenbogen )∈ Ms. : Marianne0 ≤ ≤ Kalmbach ··· ≤ ≤ 1} Sunita Bhattacharya Mrs. Jennifer M. Farner GivenPatricia numbers A. Keefe a &, Philip a , a H., a Keefe, suppose Dr. Philip S. Blau Problem 2. 1 2 3 4 Brigette McKenna Dr. Keith R. Ferland &a Mrs. is defined Gloria P. recursivelyDr. Mizan as R. Khan Mrs. Linda Bonavia Ferland n Dr. Alvin T. Kho Mr. David J. Bookston Ms. Chelsie E. Field a = (a + a Mr. + Jasona Killam+ a )/4.& Ms. Beatrice Killam Ms. Lisa M. Boone & Mr. Jeffrey M. Mr. Jonathan W. Fienup n n−1 n−2Mrs. Sandran−3 D.n−4 Kirwin IN COOPERATIONBoone WITH Mr. James B. Francis Ms. Suzanne C. Knapp Mr. Daniel D. Bourdeau Mrs. Christine P. FraserShow that the sequenceMr. Leo {R.a nKorn} converges and Q.Y. CHEN P.Miss FLAHERTY Gail Brittain O. GWILLIAM Mr. Robert F. Fredettecalculate & Mrs. Louise L = I. lim n→∞Mr. a Markn...... N. Kosmo P. HACKING J.Mr. HOROWITZ Adriano C. Bruno & Ms.S. Victoria HROBAR R. Fredette Legris Mrs. Deborah L. Krau V. LYZINSKI Ellen Gerstein I.Mary MIRKOVIC Francis Brzezenski A. MORALES Ms. Claudia E. Kulesh Mrs. Mary Ann F. GodboutProblem 3. Consider a regular tetrahedron with F. PEDIT A.Ms. RAYMOND Jennifer L. Burrill C. RUSSELL Mrs. Vicki B. Kuziak Marianne Gonzales edges of length 1. Ms.What Anna is Kye the length of the shortest N. WANG N.Ms. WHITAKER Katherine L. Burrill R. YOUNG Mr. Andrew F. Gori &loop Mrs. onDiane its M. surface Mrs. which Marilyn surrounds F. Lacerte two vertices? .. Matthew Carlyon Gori Ms. Elena I. Lamontagne Mr. Alexander R. Carpenito Mr. Douglas J. Haddad..... &...... Mrs. Rose Mr. Denis F. Lankowski The Department of MathematicsMr. James J. Chanen and &Statistics Mrs. Carol A.publishes Mary Haddad Problem 4. How many 3×3 arrays are there such Professor Lorraine D. Lavallee its annual newsletter forChanen alumni and friends. You areDr. Keith D. Hartt & thatDr. Ann (i) H. entries Wiedie include all the digits from 1 through Ms. Yue Chang Mrs. Marguerite B. Lawton important, and we want to hear from you! Please contact us atDr. David A. Hastings9, and (ii) entries in every row and column are in Mr. Yuyu Chen Mr. Donald E. Hastings Mr. Mark R. Leeper & Mrs. Evelyn C. [email protected] to share your news, let us know how increasing order? Leeper Dr. Frances M. Chevarley Mark J. Hauge you are doing, and learn ways to become involved with the Atty. John P. Letourneau & Mrs. Marcia Mr. Michael H. Cincotti & Mrs. Kristen Mr. Dominic Y. Herard Department. Our websiteD. isCincotti a valuable resource for current P. Letourneau Mr. Joseph W. Higgins & Ms. Melanie. S..Let E be the coefficients in the happenings and news, so weMr. encourageRichard D. Cocci you & to Ms. visit Alexandra us regularly Problem 5 Mrs.n Rachel M. Levy & Mr. Donald M. Higgins Levy ∞ xⁿ n at www. math.umass.eduDenosky-Smart expansion: .sec x+tan x = E . ⁿ n=0 n! Dr. Neil B. Hindman & Dr. Audrey P. Dr. Yu-Ping Li Mr. Richard A. Coco Hindman Show that they satisfy E =E =1 and for n≥1 Ms. Elizabeth W. Colby Dr. Donald F.0 Lieb1 & Mrs. Barbara T. Ms. Karol A. Hines Lieb On a more somber note,Mr. we Paul mourn M. Conlin the & Ms.passing Jill Conlin on 2 July ... Mr. Youping Huang Dr. Robin H. Lock & Dr. Patti Frazer 2018 of our dear colleagueMr. Richard D. John Coparanis S. Ellis, an internationally Mrs. Mary A. Hueser Lock regarded probabilist, andDr. a Peter good J. Costa friend to many of us onMr. Chandler Lincoln, III Mr. John M. Loughlin Mr. Boxuan Cui campus and in the community. It’s an immeasurable loss toMr. Gerald L. JanowitzProblem 6. Let AMr.n be Michael the set C. Lyle of all subsets S of our Department. For manyTheresa years Curry Richard edited the annualMr. Kaihong Jiang {1, 2, ..., n} such thatMr. BrettS contains E. Lyman the size |S| of S. Let
Newsletter and monthly News Briefs, and I — your current Bn be the set of all S in An which are minimal, i.e., editor — enjoyed working with him on both for much of the if S contains some subset T in An then T = S. Show past decade. As I re-drafted the letter soliciting briefs this that the number bn of elements of the set Bn is the 22 DEPARTMENT OF MATHEMATICS & STATISTICS th September, I realized it was based on Richard’s traditional n Fibonacci number Fn (here F1 = 1 = F2 and after text, passed down from him to me several years ago. Both that Fn = Fn−1 + Fn−2). this Newsletter and the News Briefs have become Department traditions, shaped by each of us who has taken on the role of Problem 7. Evaluate π/2 1 editor, but Richard’s influence looms large. He and I shared many common interests outside mathematics, particularly an intellectual curiosity about languages and literature, and both Send solutions, comments, or feedback via email of us have been deeply committed to carry on the tradition of to Professor Franz Pedit
2 Mrs. Carolyn M. MacArthur Mr. Ronald R. Rainka Mr. Edward A. Maybury, Sr. DEPARTMENT Mr. Adam HEAD’S B. Maidman MESSAGEMr. Barry W. Randall Dr. David L. Stenson & Dr. Ellen M. Mr. Robert Maidman & Ms. Margery Mr. Daniel Rasmussen Stenson I’d like to welcomeMaidman you to our Newsletter as the new Department Head. I officially startedIrini Stylianou on 21 January & Nikos Nikolakis 2018. It’s a true honor – and somewhat daunting – toMr. follow Adam B.in Rattiner the footsteps of Farshid Hajir, who Mr. Douglas R. Malloy Ms. Carol J. Reinhardt Ms. Mary B. Sweet & Mr. Paul A. Sweet, now serves as Vice Provost of Academic Affairs and did a fantastic job in his 3 years as Jr.Head. I take over Mr. Eduardo P. Marchena Dr. Robert R. Reitano a department that’s risen tremendously in stature since I came to UMass in 1987. We’ve Mr.made Richard some W. Tabor Mr. Brad Marcus & Mrs. Shelley F. Miss Cathleen E. Riley exceptional hires Marcusand improved our graduate and undergraduate programs. Our graduatesDr. Robert have goneM. Tardiff on & Mrs. Cindy Mr. Brian P. Riley to do outstandingMrs. things. Jacqueline We’re T. Marcusvery proud of our alumni. Tardiff Dr. Steven E. Robinson & Mrs. Claire V. Dr. James J. Tattersall & Mrs. Theresa A. Mr. Douglas V. Marquis & Mrs. Lisa Robinson Brown Marquis Tattersall A particular area of growth is our number of undergraduateMs. Josephine majors, S. Rodriguez which continually exceeds expectations. More and more of Mr. Clifford D. Martin Mr. Dorian L. Truong & Mr. Chi Q. our incoming students recognize the benefits of majoringMr. Charles in E.math. Rooney We have almost 1000Truong majors in 7 areas: Actuarial Science, Michael D. Marulis & Elizabeth T. Applied Math, Computing,Marulis Pure Math, Statistics, TeachingDr. Norman and K. an Roth Individual & Mrs. Deborah concentration. E. Mr. Peng Mathematics Wang & Ms. Yuanyuan is also an Chen essential st Roth part of any 21 centuryMr. Gerald education, F. May as over 15,000 UMass students take our classes each year.Peter Webb & Linda Webb Mr. William H. Sabean Arkady Mayblyum Mrs. Norma A. Wenkalman Mr. Gerard J. Sarnie Thanks to the hardMr. Johnwork W. of McAlister our search committee, our tenure track position in Math BiologyMr. Mark was R. Westfilled by our top candidate: Dr. Victor P. Schneider Assistant ProfessorMr. Brian John J. VanMcColgan Koten is an expert in applied probability and numerical analysis,Mrs. Carolyn performing H. White computer Ms. Jennifer Sebastian simulations of molecularMr. John J. systems McDonough with applications in biology, chemistry and materials Mr.science. Gary A. We Whitney also had a very successful Mr. Douglas J. Shaffer & Mrs. Leigh A. Mr. Jeffrey L. Whitney & Mrs. Tobi A. year in hiring 8 newMr. Williamoutstanding H. McLoughlin Visiting & AssistantMrs. Professors:Shaffer Siddhant Agrawal, Panagiota Birmpa, Noriyuki Hamada, Patricia McLoughlin Whitney Kuan-Wen Lai, Jonathan Simone, Zahra Sinaei, ZheniMr. Bernard Utic and H. Shapiro Jiayu Zhai. Our new Marshall Stone VAP, Laura Colmenarejo Mr. Jameson Davis McTaggart Mr. Gerald C. Wickham Hernando, will join us in Spring 2019. Dr. Yannan Shen Mr. Dale A. Melikan Mr. Kristopher B. Wiemer Mrs. Ann P. Sieben Mr. Daryl Miller Ms. Terry A. Wojtkunski Our Newsletter, and the on-line Faculty News BriefsDr. at Walterwww.math.umass.edu, S. Sizer provide an opportunity to highlight some of Mr. Steven A. Monahan & Mrs. Geni Ms. Sarah Cathryn Woolfrey the outstanding workMonahan of our faculty in pushing the envelopeDr. Jonathan of B.knowledge Skinner in mathematicsMr. andJohn C.statistics Yagodzinski each year: Assistant Professor Nestor Mr.Guillen Brian C. spoke Monsell at the Austin workshopDr. Howard “Gerrymandering R. Smith Steals Elections:Mr. Qiang Learn Yu how & Dr. It’s Zhixiong Done Chen and How to Stop It,” and was partMr. Patrick of a panel J. Nee on the topic includingMr. US Eric Representative T. Sondergeld Jim McGovernMrs. this Ellen year; M. Zoltoski Associate Professor Paul Hacking was invitedTerri toL. Nevillelecture & atRobert the J.2018 Neville International Congress of Mathematicians; Associate Professor Alexei Oblomkov was awarded a SimonsMr. Fellowship; Bradford S. Nichols Professors & Ms. MarkosEmily L. Katsoulakis and Luc Rey-Bellet received a major Air Force grant to develop performance guaranteesBraley in predictive modeling; Professor Andrea Nahmod was part of a feature honoring women in the Notices of the AMS; and UniversityMr. James A. DistinguishedO’Keeffe Professor Panos Kevrekidis published 4 papers in the Nature family of journals. Mrs. Corinne E. O’Reilly It’s easy to donate to the Department of Mathematics and Statistics. Our Department Mr.hosted Karnig 3 Ovianconferences & Mrs. Diana this A.past year:To makeAssociate an online Professor gift, please Anna visit Liuthe Department’s was among donations the organizers page at of the 32nd New Ovian England Statistical Symposium bringing together nearlywww.math.umass.edu/donate. 250 statisticians to discuss emerging issues in April 2018; Professor Ms. Susan C. Partyka Andrea Nahmod helped organize Women in Partial Differential Equations in March 2018; and Associate Professor Hongkun Mr. John L. Pauly If you prefer to donate by check, please make it payableth to Zhang co-organizedMr. Roy Mathematical D. Perdue Physics Perspective“UMass of Billards Amherst and Mathematics” Dominoes and celebrating mail to: the 70 birthdays of Pavel Bleher and Leonid BunimovichMs. Laurain September A. Piecz 2017. Naitian Wang Dr. Robert Piziak & Dr. Veronica K. Grant and Budget Administrator UMass Amherst undergraduatesPiziak Jonah Chaban, ArtemDepartment Vysogorets of Mathematics, and Jimmy and Statistics Hwang worked as a team, led by Assistant Professor MatthewMr. Dobson M. Amin ,Plaisted to produce the top-scoringLederle project Graduate among Research 7 competing Tower teams at the first ever Student Competition Using Modeling (SCUDEM)Mrs. Marie E. Poirier in Fall 2017. Three more710 SCUDEM North Pleasant teams Street led by Dobson also did very well in Spring 2018, receiving meritoriousMr. Robert mention Pollack and & Mrs. outstanding Lynne mention.University of Massachusetts Amherst, MA, 01003-9305 Pollack Mrs. Katherine D. Porter We are very sad to have lost an important member ofTo our learn faculty, more about Richard supporting S. Ellis the, Departmentwho passed of away Mathematics in July and 2018. Statistics, Richard joined the department inDr. 1975, Wilfredo and Quinones also taught classes in Judaism and the Torah as an adjunct professor of Judaic and Near Eastern Mr. Stuart D. Rachlin please contact Naitian Wang at [email protected] or 413-545-0095. Studies. He was an internationally regarded expert in probability and large deviation theory, who also cared very much about the well-being of his students and colleagues, organizing sessions to relieve stress both inside and outside of the classroom. Richard will be truly missed. 2018-19 Volume 34 23 We are also sorry to report the retirement of two important members of our faculty, Michael Lavine and Bill Meeks, in May 2018. Professor Lavine, a well-respected Bayesian statistician and a leader in our statistics group, had been a department member since 2008. Professor Meeks held the prestigious George David Birkhoff chair since joining the department in 1986; he is a world-renowned differential geometer and topologist, with a distinguished reputation in the area of minimal surfaces.
The support of our alumni and friends is invaluable to us. We want to know how you are doing. Please send us your news, or stop in for a visit.
– Nathaniel Whitaker
DEPARTMENT OF MATHEMATICS & STATISTICS 2018 Volume 33 3
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RISING RESEARCHER AWARD Commonwealth Honors College student Shelby Cox ’18 is a Mathematics & Statistics and Linguistics double major who has a track record of winning awards that reflect her superb academic performance and leadership abilities in the field of mathematics and statistics. Along with establishing and serving as President of the UMass chapter of the Association for Women in Mathematics, Cox has received two Outstanding Academic Achievement Awards from the Department of Mathematics and Statistics as well as the 2017 William F. Field Alumni Scholar Award, which recognizes and honors third-year students for their academic achievements. Shelby won a prestigious National Science Foundation graduate research fellowship to pursue a PhD in pure mathematics this fall at the University of Michigan.
Cox’s research accomplishments began when she participated in a summer 2016 National Science Foundation Research Experience for Undergraduates (NSF/REU) at the University of Maryland. The project concerned calculating the Euler characteristic of geometric objects, known as Hilbert schemes, which are mathematical structures in algebraic geometry that occur under symmetry. The Euler characteristic is a rough measure of the topology, or shape, of an object. The heart of Cox’s achievement was to reduce these calculations to previous known calculations that are more mathematically manageable. Cox and her collaborator gave a talk and also presented a poster on their work in January 2017 at the Joint Mathematics Meetings – the largest gathering of mathematicians in the United States and the largest annual meeting of mathematicians in the world.
According to Associate Professor Eric Sommers, her advisor and teacher, “Shelby’s superb performance in research and departmental coursework, as well as her role in establishing and leading the UMass chapter of the Association for Women in Mathematics, makes her deserving of the Rising Researcher award.”
Cox acknowledged just how much what it means to be a scientist has changed—but that the principles of science have remained the same: Girls Inc. Eureka workshop run by A. Morales, A. Raymond, G. Park and J. Selover. As we move on to new adventures as educators, actuaries, data scientists, software engineers and researchers, we probably won't have to remember the pigeonhole principle or the first 10 digits of π, but we will continue to solve problems.
Article/photo credit: Office of News and Media Relations