Duke University Math News May 13, 2012

• ♦ • SPRING 2012 EDITION • ♦ • MathDuke University News May 13, 2012 GRADUATION EDITION

were held at Cornell University, the first in 1994 and Events the second in 2008. The program was organized by Tai Melcher (Vir- ginia) and Amber Puha (San Marcos) with Rick 27th ANNUAL GEOMETRY Durrett and Jonathan Mattingly taking care of the FESTIVAL local arrangements. The workshop will feature one hour talks by The , hosted by Duke Univer- Janet Best (Ohio State), Alexandra Chronopoulou sity and UNC, was held in the Math/Physics Build- (UCSB), Cindy Greenwood (Arizona State), Alice ing from Friday, April 27, to Sunday, April 29, 2012. Guionnet (ENS Lyon), Kay Kirkpatrick (UIUC), About 75 participants from 25 universities attended Nevena Mari´c; (Missouri), Dana Randall (Geor- this event. gia Tech), Amandine V´eber (CMAP), Amy Ward The speakers this year were: (USC), and Jessica Zuniga (Duke). For more information visit the conference web page at - Simon Brendle () http://www.math.duke.edu/∼ rtd/wwp12/. ShiShi Luo, Sarah Schott, and Rachel Thomas, graduate - John Etnyre (Georgia Institute of Technology) students at the time, attended the 2008 confer- - Fernando Coda Marques (IMPA) ence at Cornell. See http://www.math.duke.edu/∼ rtd/wwp/photo08.html - Gordana Matic (University of Georgia) Alice Guionnet will present a Gergen Lecture on this visit. After many years at ENS in Lyon, Alice will be - Jan Metzger (Institute for Mathematics, Uni- moving to a faculty position at MIT in the Fall. Among versity of Potsdam) Alice’s many honors are the Rollo Davidson prize in 2003, Loeve prize in 2009, and a lecture at the ICM - Yanir Rubinstein (Stanford University) in 2006. Her thesis written under the direction of Ger- ard Ben Arous concerned the Sherrington-Kirkpatrick - Valentino Tosatti () model of spin glasses. Much of her recent work concerns - Mu-Tao Wang (Columbia University) random matrices. See her book with G. Anderson and O. Zeitouni. A continuing grant from the National Science Gergen Lecture Foundation makes it possible for us to partially re- imburse the expenses of a large number of graduate On February 28, Jordan Ellenberg gave the 2011- students, post-docs and younger faculty who do not 12 Gergen Lecture on Stability and Arithmetic have access to travel funds from other sources. The Counting Problems. conference was organized by Hubert Bray and oth- Abstract: ers in the Duke and UNC mathematics departments. A big theme in contemporary number theory is “arithmetic statistics”: what does Women in Probability the class group of a random number field The third Workshop for Women in Probability look like? What do the zeroes of a ran- will be held at Duke October 14-16, 2012. This is dom L-function look like? What does a the third conference of this series. The previous two random rational point on a variety look

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like? In this talk we will explain how in Math Physics 101. This is the department’s an- arithmetic statistics problems over func- nual opportunity for students and faculty to meet tion fields are naturally tied to topologi- and chat in an informal setting over sandwiches and cal questions about stability for homology soda. groups of certain moduli spaces; in particu- At this event, students were recognized for their lar, we will explain how a stability theorem awards and contributions to the mathematical life of for Hurwitz spaces (moduli spaces of finite the department. All in the Duke math community branched covers of the line) can be used to and especially those who are graduating are encour- prove a version of the Cohen-Lenstra con- aged to attend. jectures over function fields. Melanie and Phil Matchett Wood First Math Slam @ Duke On Thursday December 1, 2011, DUMU featured Melanie Matchett Wood ’03 with the undergraduate A Poetry Slam is when poets meet in a bar and alumni lecture The Chemistry of Primes. present their poetry to lovers of poetry. And a Math Slam is when mathematicians meet in an over- We are familiar with the prime num- crowded seminar room full of lovers of mathematics bers as those integers which cannot be fac- of all ages, career stages, and math specialties to tored into smaller integers, but if we con- present... their math! Every speaker gets 10 min- sider systems of numbers larger than the utes, a blackboard, a projector, and an audience ea- integers, the primes may indeed factor in ger to learn and be entertained at the same time. those larger systems. We discuss various Do you think you could do this? questions mathematicians ask about how The speakers of Duke’s first Math Slam – Eliza- primes may factor in larger systems, talk beth Munch, Christopher Cornwell, David Herzog, about both classical results and current re- Alan Parry, and Dave Rose - showed that social be- search on the topic, and give a sense of the havior of apes resembles vineyards, described pain- kind of tools needed to tackle these ques- less surgery with topologically non-removable fibers, tions. explained why we should love probability, told us why dark matter matters, and untied other knotty Melanie was a two time medalist at the Interna- problems. tional Mathematical Olympiad, a Putnam Fellow, Much thanks goes to Carla Cederbaum who orga- Morgan Prize winner, and American Institute of nized this first Duke math slam. Math Fellow along with many other honors. Her Duke Math shirt has been retired and hangs in the math lounge. Undergraduate News Melanie and her husband Philip are each Assis- tant Professors of Mathematics at the University of Wisconsin, Madison. In addition to the undergrad- DUMU uate lecture, each gave a more technical seminar on The Duke University Math Union has sponsored their recent research results. They brought their 18 several notable events this year such as the Duke month daughter, Abelia with them. After the Un- Math Meet, the alumni undergraduate lecture, and dergraduate Lecture, a half dozen DUMU members several social events. Many thanks to graduating took Melanie, Philip and Abelia to Parizade for an president, Vivek Bhattacharya and the other grad- entertaining conversation. uating officer. We welcome TongTong Zhan as pres- Duke Math Meet ident for the upcoming year. Nearly 400 high school students from New Jersey Student-Faculty Math Party to Georgia participated in the annual Duke Math The math undergrad/faculty party was held Meet on Saturday, November 12. About 40 Duke Thursday afternoon from 3 until 4:30 on April 26

2 Duke Math News May 13, 2012GRADUATION EDITION students helped to make up and grade the prob- universities in the 62st W.L Putnam Competition. lems, purchase and distribute the awards, serve box Daniel finished near the top of the Honorable Men- lunches, and a myriad of other tasks. tions and Vivek and Michael Banaszek were among Senior Seung In Sohn from Thomas Jefferson was the top 4% of the 4440 participants. Ben Bellis, An- the highest scorer in the contest followed by Allen drew Hertzberg, and Leslie Lei ranked among the Yang of Cary Academy, Calvin Deng of NCSSM, top 500 and David Hemminger, Joe Keefer, Kath- David Stoner and Elliott Chartock of the Columbia leen Lan, and Eugene Rabinovich were among the Math Circle, and Brendan Fletcher of the Charlotte top 20% of the 4440 participants. Math Club. Harvard won the contest this year followed by The team from Columbia Math Circle took first Carnegie Mellon, Cal Tech, Stanford and MIT. The prize followed by a team from NCSSM, two teams median score was 0 and only 25% of participants from AAST and a team from Thomas Jefferson SST. scored 3 or more points. MCM ACM Programming Three Duke teams were among nearly 3,700 teams The ACM International Collegiate Programming of undergraduates from around the world to partici- Competition (ACM-ICPC) is an annual program- pate in the 2012 International Mathematics Contest ming competition involving several thousand teams in Modeling. Freshman Leslie Lei and Juniors Tian- from universities all over the world. This year, xiang Xiong and Dazhong (Chime) Xuan garnered a team from Duke University placed first out of a Meritorious (top 10%) ranking while the teams of over 160 teams in the Mid-Atlantic Regionals of the sophomores Aashiq Dheeraj, Xiaoyu (Mandy) Jiang ACM-ICPC, thereby qualifying for the World Fi- and Kathleen Lan and the team of freshmen David nals. The team of three, Joe Keefer (Math/Econ Hemminger, Logan Su, and Christy Vaughn received ’12) and two graduate students from the Computer Honorable Mention for their solutions. Science Department along with Assistant Coach, Each Duke team derived a method to schedule 6 Siyang Chen (Math/CS ’12), will travel to Warsaw, to 18 day trips along the Big Long River so as to Poland, this May for the finals to compete against maximize the wilderness experience and minimize about 100 other teams. Duke University has quali- the overlap with other groups. The teams used var- fied for the World Finals every year except one since ious combinatorial methods such as the asymmetric 1994. travelling salesman problem and genetic algorithms Datafest to arrive at an efficient means for scheduling the trips during the busy summer months. The inaugural DataFest was held this April. In this competition, teams of undergraduates work for Menger Prize 48 hours to analyze a large and complex dataset. The Menger Prize, named for renowned Austrian This year’s theme was micro lending. Participants mathematician Karl Menger, is awarded to the stu- analyzed six years of data from Kiva.com on lenders, dents with the best score on the W.L. Putnam borrowers, loans and their field partners with the Mathematical Competition. The winners this year goal of making recommendations to a Kiva user or are Daniel Vitek ’14, Michael Banaszek ’13, and discovering insights into Kiva or micro lending in Vivek Bhattacharya ’12. general. The team of Dazhong (Chime) Xuan, Christine Julia Dale Prize Cheng, Tianxiang Xiong, Tori Reynolds, and Dy- The winners of the 2012 Julia Dale Prize for excel- lan Britt won the prize for best visualization. See lence in mathematics are Vivek Bhattacharya, and . http://stat.duke.edu/datafest Veronica Ciocanel. This is the highest honor offered Putnam Competion by the mathematics department. The team of Vivek Bhattacharya, Leslie Lei and Veronica, a Mathematics and French major who Daniel Vitek finished 16th among 572 colleges and comes to us from Romania, was Finalist both for

3 Duke Math News May 13, 2012GRADUATION EDITION the Mathematics Contest in Modeling and for the • Kyu Won Choi - Relative contributions of com- Faculty Scholarship. She has written two major re- mon jumps in realized correlations search papers soon to be published and has been awarded graduation with distinction for her pa- • Veronica Ciocanel - Analysis of the nonlinear per with Tom Witelski on the non-linear dynam- dynamics of the forced planar string pendulum ics of a pendulum on a string. Veronica also com- • Kaveh Danesh - A branching process model for pleted a major research project with Mike Reed on ovarian cancer the genetic conflict involved in gestational diabetes. Veronica will attend Brown University to continue • Theo Frehlinghuysen - Carbon sequestration via her study of applied mathematics. forest management techniques Vivek is an Economics and Physics major who has more than fulfilled the requirements for a ma- Duke Faculty Scholarship jor in Mathematics. He has been coordinator of the Duke Math Meet, twice a Finalist on the Mathemat- Vivek Bhattacharya was one of two Faculty Schol- ics Contest in Modeling, a two time winner of the ars this year. Although an Economics and Physics Menger prize, a Faculty Scholar, and is currently major, Vivek has taken more than enough courses to president of DUMU. Vivek will continue his study qualify as a math major were triple majors allowed of Economics at MIT. in Trinity College. Mathematics and French Stud- The freshman Julia Dale prize is awarded to the ies major Veronica Ciocanel was one of two students first year students who have most distinguished named Honorable Mention in this the highest award themselves in mathematics. The winners this year that the Duke faculty can bestow on its undergrad- are David Hemminger, Leslie Lei Lei and Eugene uates. Rabinovich. Each has excelled in advanced under- New Course graduate courses this year. Ingrid Daubechies, Jonathan Mattingly, and Ezra PRUV Miller are team-teaching a new course this year, Ben Bellis, Adrian Chan, Kyu Won Choi, Veron- Math 81: “Math Everywhere”. ica Ciocanel, Kaveh Danesh, Theo Frehlinghuysen, Yingyi Shen, and Danny Thielman have written se- Math Ment ring nior theses this year and will give talks on their re- Initiated by Christine Berkesch,♀ Carla Ceder- search to the Duke math community. Most of these baum, Benjamin Cooke, and Sarah Schott, the students received stipends through the PRUV Fel- Department of Mathematics and the Academic low program. New PRUV Fellows are Bryan Jacob- Resource Center will together offer a mentoring son, Mandy Jiang, Kathleen Lan, Ivy Shen, Daniel program for female first-year students interested in Stern, and Daniel Vitek. math. Starting in the coming Fall, this program pairs female first-years who declared an interest in Graduation with Distinction in mathematics with upperclass women pursuing a Mathematics major or minor in math. The goal of the program Six math majors will graduate with distinction is to increase identification and retention among this May. our female students. We are still looking for more mentors! • Ben Bellis - Investigation of a local computa- tion of the signature from the triangulation of To sign up for the program as mentor or mentee, a manifold please visit http://www.math.duke.edu/mentors/, or if you have any questions, you can contact the organizers • Adrian Chan - Pricing financial derivatives via [email protected]. with multi-task machine learning and mixed ef- fects methods

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Elizabeth Munch won the first Jo Rae Wright Fel- Graduate Student News lowship for Outstanding Women in Science. See http://today.duke.edu2011/12/wright/ Graduating Ph.D. Students in -fellowships 2011-12 Congratulations to our graduate students who Faculty News defended their doctoral theses this year. Each has accepted an academic position for the upcoming year. They, their advisors and their positions are: James B. Duke Professor of Mathematics Ingrid Daubechies received the Okawa Prize for her Prakash Balachandran has accepted a postdoc outstanding and pioneering contributions to the position at Boston University theory and applications of wavelets. See more at Advisor: Jonathan Mattingly http://www.okawa-foundation.or.jp/en/activities /prize/list.html Graham Cox is a Lorenz postdoc at the University She has also been awarded the 2012 Nemmers of North Carolina, Chapel Hill. prize for academic excellence in mathematics. This Advisor: Hugh Bray award carries a $150,000 stipend and the scholar spends 10 weeks in residence at Northwestern Uni- Esteban Chavez has accepted a postdoc position versity. See http://en.wikipedia.org/wiki/ at UC Santa Barbara. Nemmers Prize in Mathematics. Advisor: James Nolen Retirements Kevin Gonzales is Assistant Professor at Shaw Jack Bookman University After 30 years at Duke, Jack Bookman will retire Advisor: David Schaeffer this spring as Professor of the Practice of Mathemat- ics. In addition to teaching many first and second Tiffany Kolba will be an Assistant Professor at year mathematics courses, Jack has coordinated the Valparaiso University training of graduate student instructors and devel- Advisor: Jonathan Mattingly oped methods to evaluate many of the reform cal- culus programs around the country. He has advised Michael Pruitt has a postdoc position at the undergraduates interested in teaching at secondary University of Connecticut schools and taught education courses for them. Jack Advisor J Thomas Beale has published 22 articles on mathematical education and given numerous talks at national conferences. David Rose will be Busemann Assistant Professor He plans to continue to write and speak about cal- at the University of Southern California culus teaching reform and teacher and student as- Advisor: Lenny Ng sessment.

Sarah Schott will be Assistant Professor of the David Schaeffer Practice at Duke University In June, Dave Schaeffer will retire from the Mathe- Advisor: Mark Huber matics Department. He grew up in Cincinnati, was an undergraduate at the University of Illinois, and Shishi Luo received the Katherine Goodman Stern received his Ph.D. from MIT in 1968, under the su- Fellowship for the period of September 1, 2012 to pervision of Takeshi Kotake. May 31, 2013. This fellowship, awarded by the After ten years at Brandeis and back at MIT, he Graduate school, covers a year’s stipend for final came to Duke in 1978, and he was appointed James year PhD students. B. Duke Professor of Mathematics in 1990. “It has

5 Duke Math News May 13, 2012GRADUATION EDITION been very gratifying to participate in the dramatic academic calendar; he is exploring opportunities for improvement of this department over that period,” volunteer work, including tutoring (“I know I am go- he reflects. ing to miss working with students,” he laments); he Throughout his career Schaeffer studied prob- plans to take up something wholly new like learning lems of various kinds involving differential equa- to draw or becoming fluent in Spanish. tions, both ordinary and partial. Starting from a “How am I going to find time to do all that stuff?” fairly “pure” focus, he moved consistently towards he muses. more applied problems over the years. His most widely cited research was in bifurca- tion theory, culminating in the two-volume mono- graph Singularities and Groups in Bifurcation The- ory, with Marty Golubitsky and Ian Stewart. Later work introduced the subject of granular flow to the mathematics and physics communities, and this area has grown to a major subfield. More recently he has been interested in mathematical biology, especially problems in cardiac dynamics. Schaeffer directed 14 Ph.D. theses while at Duke, and he supervised several postdoctoral associates, in Math and other departments. But perhaps his best known educational contribution, at least lo- cally, was his innovative case-study course in mathe- matical modeling. In this course he introduced math graduate students to mathematical issues in the re- search area of a professor in another department at Duke, and he guided them towards performing inde- John Trangenstein pendent research in this area by the end of the term. After 21 years at Duke, John Trangenstein has He taught the course about a half dozen times, each freed himself from administrative and teaching re- semester with a different focus. Several Ph.D. theses sponsibilities. He plans to devote more time to in diverse areas grew out of this course, and in fact writing an interactive book on Scientific Computing, Schaeffer’s own late-career work in electrocardiology studying Chinese with thoughts of giving lectures at 1 arose through it. Jiao Tong University in Shanghai and especially to In collaboration with his former student John enjoy sailing. He is happy to be able to sail when- Cain (now at the University of Richmond), Schaeffer ever the weather is good, not just when his schedule is writing an introductory graduate ODE textbook. is open. This book, which will be freely available on the in- Trangenstein wrote his PhD in 1975 with Jim ternet, is based on the course he taught for over a Bramble at Cornell and then taught at UCSD for decade, all the while dissatisfied with the available 4 years. After a series of research positions at a texts. In fact, even in retirement, he will teach this small defense consulting firm, Exxon Production Re- course a few more times in order to get student feed- search, and Lawrence Livermore National Labora- back on the manuscript. tory, he accepted a faculty position at Duke While not ready to give up research, he is also While at Duke, Trangenstein supervised 4 PhD looking forward to pursuing neglected interests like students and published 2 books with Cambridge sailing, piano, and non-mathematical reading; he University Press (Numerical Solution of Hyperbolic welcomes the chance to get enough exercise; he is Partial Differential Equations in 2009, and Numer- relishing the prospects of travel unhampered by the ical Solution of Elliptic and Parabolic Partial Dif- 1This course was written up in the Notices of the AMS 43 ferential Equations in 2012). (1996), p550 and in SIAM Review 40 (1998), p356.

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Mr. Travis Wade Byington Math Degree Candidates, Mr. Alejandro Javier Cortese Academic Year 2011–12 Ms. Natalie Ann Dorrow Mr. Yong-Hui Goh First Majors Mr. Nathan Christopher Klug Mr. Mingwei Lei Mr. Dea Yong Park Mr. Ben Bellis Mr. Gaurav Nath Sabharwal Ms. Callie Merriam Berkowitz Mr. Hao Sun Mr. Scott David Brothers Mr. Ross Jackson Sylvester Mr. Dae Hyun Byun Mr. Trevor Kennedy Terris Mr. Nathan Thomas Carlin Mr. Peichun Wang Mr. Alexander Jaekwon Cha Mr. Yu-Po Wong Mr. Adrian Chan Mr. Fengqi Xu Mr. Siyang Chen Mr. Yunze Chen Ms. Kyu Won Choi Minors Ms. Veronica Maria Ciocanel Mr. Kaveh Danesh Mr. Daniel Patrick Ahrens Mr. Sean P. Dillard Mr. Peter Bartlett Bastian Mr. Tyler Xavier Donahue Mr. Adam Bennett Mr. Theodore John Frelinghuysen Mr. Samuel Isaac Berchuck Mr. Timothy Parkman French Mr. Vivek Bhattacharya Mr. Michael Bradley Goodrich Mr. Sami Boghos Mr. Michael Seth Jaffe Mr. Ronald Cass Mr. Joseph John Keefer Mr. Meng-Yang Chen Mr. Daniel Martin Kindya Mr. Austin Ross Ely Ms. Anna Y. Kuznetsova Mr. Julian Zachary Genkins Mr. Boris Tsz Hin Lau Ms. Sarah Holle Gustafson Mr. Donovan Wen Min Lee Mr. Robert Davis Helms Ms. Lingfeng Li Mr. Jacob Rueywen Hwang Mr. You Li Ms. Alyson Elaine Johnson Ms. Leslie Irene Morrison Mr. Jordan Kassof Mr. Keunyoung Oh Mr. Alexander Jacob Kritchevsky Mr. Michael Diego Osorio Mr. John Liu Mr. Ethan Haddox Pollard Mr. Yong Chuan Roger Look Mr. David Benjamin Reynolds Mr. Ryan Michael Magee Mr. Scott Benjamin Rich Mr. Amaan Amjad Mitha Mr. Michael Schuyler Rock Ms. Nicole Rose Page Ms. Yingyi Shen Mr. Jeffrey Peyser Mr. Matthew Ryan Straus Mr. Sameer Prasada Ms. Ana-Maria Kirilova Tenekedjieva Mr. Vijay Ram Mr. Daniel Wilson Thielman Mr. Tyler Rohr Mr. Shengyan Wang Mr. Shreyan Sen Ms. Lauren Shwisberg Ms. Allison Lara Stashko Second Majors Mr. Jack H. Stringfield Mr. Bruce Sun Mr. Nicholas Woody Bodnar Ms. Shuting Wei

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Ms. Meng Xie Duke Math News Mr. Edward Yi The Duke Math News is published several times a Ms. Hazal Yuksel year and is distributed to those in the Duke mathe- Mr. Samuel Hoy Zimmerman, III matics community. For previous editions and other news, see http://www.math.duke.edu/news/. We Master of Arts welcome items of interest for our next issue. Send them to [email protected] or [email protected] Ms. Caitlin J. Leverson To read about other news, honors and events con- Mr. Alexander D. Pruss cerning mathematics at Duke, visit http://www. Mr. Joseph John Schmitt math.duke.edu/news/. The on-line calendar at http://www.math.duke.edu/mcal lists both regu- lar and special seminars and colloquia for the up- Ph.D. coming weeks. The department maintains video archives of talks, lecture series and special confer- Dr. Esteban Alejandro Chavez ences at Duke, many of which are available, on- Dr. Tiffany Nicole Kolba line. See http://www.math.duke.edu/computing/ Dr. David Emile Rose broadcast.html for more information. Dr. Sarah Jane Schott —David Kraines, DMN Faculty Sponsor

Faculty Sponsor David Kraines ...... [email protected] Production Manager Bonnie E. Farrell ...... [email protected] Department of Mathematics Box 90320 Durham, NC 27708-0320 http://www.math.duke.edu/math news/

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