DOCSLIB.ORG

Extra Dimensions and Warped Geometries Lisa Randall

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Extra Dimensions and Warped Geometries Lisa Randall S PACETIME REVIEW Extra Dimensions and Warped Geometries Lisa Randall The field of extra dimensions, as well as the hypothesized sizes of extra area of a sphere drawn at the distance r dimensions, have grown by leaps and bounds over the past few years. I (because all force lines penetrate the sphere’s summarize the new results and the reasons for the recent activity in this surface). Because the gravitational force be- field. These include the observations that extra dimensions can be mac- tween two masses is proportional to the prod- roscopic or even infinite in size. Another new development is the appli- uct of their masses, the 1/r 2 form of the force cation of extra dimensions to the determination of particle physics pa- law has important consequences for heavy rameters and properties. macroscopic objects, such as planets. The force law is also measured on very small We generally take it for granted that we live balls (compactification) or the more recent scales with much smaller objects. Here, the in a world where there are three infinite spa- proposal by Sundrum and myself of focusing weakness of gravity is in evidence, and other, tial dimensions. In fact, we rarely give this of the gravitational potential in a lower di- stronger forces can interfere with the mea- fact much thought; we readily refer to left- mensional subspace (localization) (3, 4). surement. The best measurement to date right, forward-backward, and up-down. These ideas are important in and of them- comes from an impressively accurate exper- Yet the most exciting developments in selves; one or the other would be the reason iment by Adelberger’s group at the Universi- particle physics in the past few years have we so far haven’t observed evidence for extra ty of Washington (6), where it has been involved the recognition that additional di- dimensions, should they exist. I then go on to determined that the 1/r 2 force law persists mensions might exist and furthermore might explore another exciting development in the down to distances on the order of a 10th of a play a role in determining our observable field of extra dimensions. This is the fact that millimeter. Deviations from this form on world. New theoretical discoveries are evolv- even though the dimensions have not yet shorter distance scales are not excluded. ing at a very rapid rate. As we will see, the been seen directly, their existence might ex- This means that according to detailed ex- potential implications range from experimen- plain important features of the observed stan- perimental observations, physics appears to on October 15, 2010 tal signatures of extra dimensions, to under- dard model and will be observed in the near reflect three spatial dimensions on distance standing fundamental questions about the na- future should these conjectures prove correct. scales ranging from a 10th of a millimeter to ture of gravity, to new insights into the evo- astrophysical and probably cosmological dis- lution of our universe. Hidden Dimensions tances. Were there more than three spatial One of the chief motivations for consid- Before proceeding, it is useful to describe dimensions, the gravitational force should ering additional dimensions came from string several of the ways in which we determine spread out in all these dimensions, and the theory, which in turn is motivated by the that there are three dimensions of space. Cer- force law would fall off faster, 1/r3 say, for failure of classical gravity to work at very tainly, that is all that we see at a casual one additional spatial dimension. Somehow, short distance scales or, equivalently, at very glance, but science often consists of probing in order to agree with what we observe, this high energies, where quantum mechanical ef- beyond what is manifestly “evident.” The key better not be the case, and was one of the first www.sciencemag.org fects cannot be neglected. The only known to understanding the experimental and astro- issues that needed to be addressed when ad- way to consistently reconcile quantum me- physical determination of the dimensions of ditional dimensions were suggested. chanics with Einstein’s theory of gravity is space is to consider the gravitational force Kaluza first proposed an additional di- string theory, in which the fundamental ob- law that says that the force between two mension in his attempt to reconcile electro- 2 jects that constitute our universe are not par- masses is GNm1m2/r , where r is the separa- magnetism and gravity (1). His additional ticles but (very tiny) extended objects: tion between the two masses. I use units dimension had finite size; there are three h ϭ ϭ strings. In what follows, I use very little of where ( /2␲) c 1(h, Planck’s constant; c, infinite spatial dimensions, but a fourth one is Downloaded from the full formalism that has been developed to the speed of light). Newton’s constant, GN,is trapped in a circle of size rc in the extra describe string theory. However, I am moti- (10Ϫ33 cm)2, which is very small. It is in- dimension. Einstein, the referee of the paper, 2 vated by one very important fact. It appears versely proportional to MP , where MP, the objected that the size of this additional di- that one can only have a consistent string Planck mass, is about 1019 GeV. This mass mension was not determined. Publication was theory that can describe the known particles scale appears because it is associated with the delayed until 1926, when Klein observed that if there are many additional spatial dimen- graviton coupling, where the graviton is the a circle of size determined by the Planck sions: six or seven, depending on how one spin-2 particle that mediates the gravitational scale, 10Ϫ33 cm, is completely unobservable looks at it. The question is, then, why don’t force (5). Such energies can only be probed at (2). This is readily understood intuitively; we see these additional directions? What has the very tiny Planck length, 10Ϫ33 cm. The dimensions whose size we cannot resolve are become of them? Can they play any role in position dependence of the force law is readi- observationally indistinguishable from no ex- the physics we see? And is there any chance ly understood as a consequence of the isotro- tra dimension at all. One common example to we will observe them soon? py of space—the fact that the laws of physics illustrate this is a garden hose; as viewed at a Here I describe the two known ways to do not distinguish any particular direction. distance, it appears to be one dimensional. incorporate additional dimensions of space Imagine that one can draw the gravitational However, up close, one readily perceives that that are consistent with what we see, or rather force as a set of lines emanating in all direc- there are three dimensions. From the vantage what we don’t see; namely Kaluza’s (1, 2) tions from a massive source, so that the den- point of the force law argument given above, original idea of curling them up into little sity of lines determines the strength of the force law can be consistent with what we gravity. observe because isotropy is violated; the di- It is clear that as we measure the force at mensions of finite size are readily distin- Jefferson Physical Laboratory, Harvard University, Cambridge, MA 02138, USA. E-mail: randall@physics. increasing distance r, the strength is propor- guished from the “compactified” circular ex- harvard.edu tional to 1/r 2, or the inverse of the surface tra dimension. The force lines can only 1422 24 MAY 2002 VOL 296 SCIENCE www.sciencemag.org S PACETIME spread a distance rc in the extra dimension. Planck mass are relevant. So it is too limiting to additional dimensions, because electromag- At larger distances, the force appears to be restrict ourselves to Planck-scale compactifica- netism, which is extremely well studied, be- just that of a four-dimensional (three space tion. If other possibilities exist, they should be haves just as it would in four dimensions, plus one time) universe. This argument can explored. In fact, experimental constraints tell regardless of the size of the additional dimen- also be used to see how the Planck scale of us only that the extra dimensions must be small- sions. However, the mechanism that confines a four-dimensional world is related to that er than about 10Ϫ16 mm, corresponding to the electromagnetism to the brane cannot be ap- of a higher dimensional world. In the n- mass scale 103 GeV probed by current particle plied to gravity; gravity must exist in the dimensional world, the force law dies off experiments. This means that from an experi- “bulk”; that is, the full spacetime. One way of with r as 1/rnϪ2 and is inversely propor- mental point of view, we really have no idea understanding this is that the graviton is con- tional to the higher dimensional “Planck” whether the dimensions are as small as the nected to the full spacetime geometry and is mass that determines the strength of the Planck length. They can be 16 orders of mag- coupled to energy anywhere. higher dimensional gravity, raised to the nitude larger [see (7) for example]. So the picture of ADD is that space is power n Ϫ 2. Because we average over the In fact, that is not the last word on the bounded by branes, where the standard model extra dimensions to see an effective lower possible size of extra dimensions. One of particles (but not gravity) are confined.
Load more

Recommended publications
  • Dark Matter and the Dinosaurs: the Astounding Interconnectedness of the Universe Pdf, Epub, Ebook
    DARK MATTER AND THE DINOSAURS: THE ASTOUNDING INTERCONNECTEDNESS OF THE UNIVERSE PDF, EPUB, EBOOK Lisa Randall | 432 pages | 05 Jan 2017 | Vintage Publishing | 9780099593560 | English | London, United Kingdom Dark Matter and the Dinosaurs: The Astounding Interconnectedness of the Universe PDF Book Randall rebuts such criticism by noting that it could be "simpler to say that dark matter is like our matter, in that it's different particles with different forces", adding "the other answer is that the world's complicated, so Occam's razor isn't always the best way to go about things. There was a problem filtering reviews right now. Creo que su lectura es muy recomendable. So if, in fact, there is this dense, dark disk, there should be evidence for it in this data, which will be really exciting. Amazon Second Chance Pass it on, trade it in, give it a second life. Retrieved 12 December Or, if you are already a subscriber Sign in. Randall: I mean there is, of course, also the richness of how the pieces fit together, which is the wonderful stuff that we observe in the world. And second, once we have them, what are all the consequences? Randall conjectures that dark matter may have indirectly led to the extinction of dinosaurs. And those are worth drilling down and really focusing on. Introduction is nice and smooth. And we can see how that fits together and then how that came about and try to understand that with science, over time. Baird, Jr. Although I am left confused to wether there is evidence for periodicity or not.
    [Show full text]
  • Understanding a Warped Cosmos
    Lisa Randall. “One challenge today is to see what you can do with large amounts of data, to study fundamental properties, not just questions of how electromagnetism gives rise to certain things. Can we actually see deviations from what you would predict in conventional theories?” Rami Shllush Understanding a warped cosmos What’s the connection between dinosaurs and dark matter? What is the glue that holds the universe together? Is there a fourth - and fifth - dimension? These are just some of the questions that occupy Lisa Randall, the first female physicist to get tenure at Princeton, Harvard and MIT ■ ״ ״r* י •• 1 י׳ The CERN facility, near Geneva. “We need higher-energy machines and particle Illustration of a large asteroid colliding with Earth over the Yucatan Peninsula, in accelerators,” says Randall, “but to really see new things, we need even more Mexico. The impact of such occurrences are thought to have led to the death of the powerful machines.” Richard Juillian/AFP dinosaurs some 65 million years ago. Mark Garlick/Science Photo Libra Ido Efrati in the sciences. In 2016 he mystery of the universe,be seen as evidence that dark matter Over the years, studies have specializes interview with The New she and the many riddles that re- interacted in some way with hydrogen mapped the presence of dark matter Yorker, related that in her teens she had fre- main open about itcan be ex- atoms, thus leadingto the loweringof in various placesin the universe,in- the of the dark matter. our emplifiedin myriad ways. temperature eludingin the center of galaxy,the quent confrontations with her mother, to One of the most frustratingPhysicistsresponding the article Milky Way.
    [Show full text]
  • Minutes High Energy Physics Advisory Panel October 22–23, 2009 Hilton Embassy Row Washington, D.C
    Draft Minutes High Energy Physics Advisory Panel October 22–23, 2009 Hilton Embassy Row Washington, D.C. HEPAP members present: Hiroaki Aihara Wim Leemans Marina Artuso Daniel Marlow Alice Bean Ann Nelson Patricia Burchat Paris Sphicas Lance Dixon Kate Scholberg Graciela Gelmini Melvyn J. Shochet, Chair Larry Gladney Henry Sobel Boris Kayser Maury Tigner Robert Kephart William Trischuk Steven Kettell Herman White HEPAP members absent: Priscilla Cushman Lisa Randall Sarah Eno Sally Seidel Stephen Olson Also participating: Barry Barish, Director, Global Design Effort, International Linear Collider Frederick Bernthal, President, Universities Research Association Glen Crawford, HEPAP Designated Federal Officer, Office of High Energy Physics, Office of Science, Department of Energy Joseph Dehmer, Director, Division of Physics, National Science Foundation Cristinel Diaconu, Directeur de Recherche, IN2P3/CNRS, France Robert Diebold, Diebold Consulting Marvin Goldberg, Program Director, Division of Physics, National Science Foundation Judith Jackson, Director, Office of Communication, Fermi National Accelerator Laboratory Young-Kee Kim, Deputy Director, Fermi National Accelerator Laboratory John Kogut, HEPAP Executive Secretary, Office of High Energy Physics, Office of Science, Department of Energy Dennis Kovar, Associate Director, Office of High Energy Physics, Office of Science, Department of Energy Kevin Lesko, Nuclear Science Division, Lawrence Berkeley National Laboratory Marsha Marsden, Office of High Energy Physics, Office of Science,
    [Show full text]
  • January 26, 2009
    INFORMATION Texting, blogging and the like might yet prove beneficial, 3 BIOLOGICAL SCIENCE Avian dads learned doting ways from the dinosaurs, 4 CENTER FOR TEACHING AND LEARNING Lectures, workshops and The Faculty-Staff Bulletin of The Florida State University consultations, 6 and 7 VolumeSTATE 43 • Number 10 January 26 - February 15, 2009 Florida State pays tribute to ‘Year of Science’ ORIGINS ’09 Two-time Pulitzer Prize-winning au- Wilson will join acclaimed Harvard NPR’s “Science Friday,” among many thor and world-renowned biologist E.O. University cosmologist Lisa Randall, others for the program, which begins Wilson will be among the headliners of famed anthropologist Don Johanson (co- March 16. a two-week celebration of what discov- discoverer of “Lucy”, the world’s most Named “Origins ’09: A Celebration eries in science and the humanities have famous fossil), Sean B. Carroll, noted of the Birth and Life of Beginnings,” the meant to modern civilization. biologist and author, and Ira Flatow of event is being sponsored by the Florida State University Office of Research and co-sponsored by the FSU College of Medicine and the Tallahassee Scientific Conference headliners will Society. It’s all part of a tribute to 2009 include, clockwise, E.O. as the Year of Science, a national desig- Wilson, the world’s leading nation inspired by the 200th birthday of Charles Darwin (Feb. 12). naturalist, Harvard physicist Unlike many tributes scheduled Lisa Randall and Ira Flatow, around the nation and world, Florida host of “Science Friday” on State’s program is designed to go be- National Public Radio.
    [Show full text]
  • Curriculum Vitae
    CURRICULUM VITAE Raman Sundrum July 26, 2019 CONTACT INFORMATION Physical Sciences Complex, University of Maryland, College Park, MD 20742 Office - (301) 405-6012 Email: [email protected] CAREER John S. Toll Chair, Director of the Maryland Center for Fundamental Physics, 2012 - present. Distinguished University Professor, University of Maryland, 2011-present. Elkins Chair, Professor of Physics, University of Maryland, 2010-2012. Alumni Centennial Chair, Johns Hopkins University, 2006- 2010. Full Professor at the Department of Physics and Astronomy, The Johns Hopkins University, 2001- 2010. Associate Professor at the Department of Physics and Astronomy, The Johns Hop- kins University, 2000- 2001. Research Associate at the Department of Physics, Stanford University, 1999- 2000. Advisor { Prof. Savas Dimopoulos. 1 Postdoctoral Fellow at the Department of Physics, Boston University. 1996- 1999. Postdoc advisor { Prof. Sekhar Chivukula. Postdoctoral Fellow in Theoretical Physics at Harvard University, 1993-1996. Post- doc advisor { Prof. Howard Georgi. Postdoctoral Fellow in Theoretical Physics at the University of California at Berke- ley, 1990-1993. Postdoc advisor { Prof. Stanley Mandelstam. EDUCATION Yale University, New-Haven, Connecticut Ph.D. in Elementary Particle Theory, May 1990 Thesis Title: `Theoretical and Phenomenological Aspects of Effective Gauge Theo- ries' Thesis advisor: Prof. Lawrence Krauss Brown University, Providence, Rhode Island Participant in the 1988 Theoretical Advanced Summer Institute University of Sydney, Australia B.Sc with First Class Honours in Mathematics and Physics, Dec. 1984 AWARDS, DISTINCTIONS J. J. Sakurai Prize in Theoretical Particle Physics, American Physical Society, 2019. Distinguished Visiting Research Chair, Perimeter Institute, 2012 - present. 2 Moore Fellow, Cal Tech, 2015. American Association for the Advancement of Science, Fellow, 2011.
    [Show full text]
  • Supergravity on the Brane
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by CERN Document Server Supergravity on the Brane A. Chamblin∗∗ & G.W. Gibbons DAMTP, Silver Street, Cambridge, CB3 9EW, England (November 23, 1999) We show that smooth domain wall spacetimes supported by a scalar field separating two anti- de-Sitter like regions admit a single graviton bound state. Our analysis yields a fully non-linear supergravity treatment of the Randall-Sundrum model. Our solutions describe a pp-wave propa- gating in the domain wall background spacetime. If the latter is BPS, our solutions retain some supersymmetry. Nevertheless, the Kaluza-Klein modes generate \pp curvature" singularities in the bulk located where the horizon of AdS would ordinarily be. 12.10.-g, 11.10.Kk, 11.25.M, 04.50.+h DAMTP-1999-126 I. INTRODUCTION full dynamics of the domain wall is not treated in detail in the Randall-Sundrum model. In fact gravitating domain walls have a drastic effect on the curvature of the ambi- It has long been thought that any attempt to model ent spacetime and it is not obvious that a simple model the Universe as a single brane embedded in a higher- involving a single collective coordinate representing the dimensional bulk spacetime must inevitably fail because transverse displacement of the domain wall is valid. the gravitational forces experienced by matter on the For these reasons it seems desirable to have a simple brane, being mediated by gravitons travelling in the non-singular model which is exactly solvable. It is the bulk, are those appropriate to the higher dimensional purpose of this note to provide that.
    [Show full text]
  • Doctora Honoris Causa Lisa Randall
    Doctora honoris causa Lisa Randall Doctora honoris causa LISA RANDALL Discurs llegit a la cerimònia d’investidura celebrada a la sala d’actes de l’edifici Rectorat el dia 25 de març de l’any 2019 Índex Presentació de Lisa Randall per Àlex Pomarol Clotet 5 Discurs de Lisa Randall 13 Discurs de Margarita Arboix, rectora de la UAB 21 Curriculum vitae de Lisa Randall 27 Acord de Consell de Govern 131 PRESENTACIÓ DE LISA RANDALL PER ÀLEX POMAROL CLOTET És un plaer ser el padrí de la professora Lisa Randall, una persona que ha destacat per les seves contribucions en el camp de la física de partícules Les teories proposades per la professora Lisa Randall han mirat de resoldre alguns dels problemes més importants dins de la física de partícules i han inspirat una àmplia gamma de cerques ex- perimentals, especialment en el gran col·lisionador de partícules LHC del CERN a Ginebra, però també dins de l’àmbit astrofísic, motivades per les seves propostes per l’origen de la matèria fosca de l’univers Tot i això, l’interès de la professora Lisa Randall s’ha estès més enllà de la recerca d’avantguarda i també s’ha centrat a transmetre aquests coneixements al públic general Això ho ha fet possible no sols grà- cies als seus llibres de divulgació sinó també mantenint una estreta col·laboració amb artistes per obrir nous camins per portar al públic les idees científiques. En aquest aspecte, la professora Lisa Randall ha sabut relacionar els coneixements del seu camp amb els de la filosofia, les humanitats i la música, com veurem a continuació Professor
    [Show full text]
  • Warped Passages : Unravelling the Universes Hidden Dimensions Pdf, Epub, Ebook
    WARPED PASSAGES : UNRAVELLING THE UNIVERSES HIDDEN DIMENSIONS PDF, EPUB, EBOOK Lisa Randall | 512 pages | 03 Aug 2006 | Penguin Books Ltd | 9780141012971 | English | London, United Kingdom Warped Passages : Unravelling the Universes Hidden Dimensions PDF Book Rather than seeking to create an all-encompassing theory, she develops models - mini-theories that target specific problems and that might then point the way to a more general theory. Warped Passages: Unraveling the Mysteries of the Universe's Hidden Dimensions is the debut non-fiction book by Lisa Randall , published in , about particle physics in general and additional dimensions of space cf. Show More Show Less. Randall's perspective as a woman in a field where men hold 90 percent of all faculty positions makes for some wry comments. This category only includes cookies that ensures basic functionalities and security features of the website. Randall, a theoretical physicist at Harvard, writes from the trenches: She has been working on higher dimensional models of the universe for several years now. Show More Show Less. Most relevant reviews. A gateway to a world of limitless possibilities. Randall, though, argues that without any experimental feedback, string theorists may never reach their goal. She observes that when people develop an understanding of the science of particle physics and the experiments that produce the science, people get excited. Subscribe to our YouTube Channel. Ninety years after the historic double-slit experiment, the quantum revolution shows no sign of slowing. Can music also repair broken networks, restore memory, and strengthen the brain? I guess she is doing all this to better describe multi-dimensions at the end of the book since you probably need to know a good deal of particle physics before she does that.
    [Show full text]
  • The Emergence of Platonism in Modern Physics
    TRANSCENDENTAL MINDS AND MYTHICAL STRINGS: THE EMERGENCE OF PLATONISM IN MODERN PHYSICS. by Daniel Bernard Gopman A Thesis Submitted to the Faculty of The Wilkes Honors College in Partial Fulfillment of the Requirements for the Degree of Bachelor of Arts in Liberal Arts and Sciences with a Concentration in History Wilkes Honors College of Florida Atlantic University Jupiter, Florida May 2008 ii TRANSCENDENTAL MINDS AND MYTHICAL STRINGS: THE EMERGENCE OF PLATONISM IN MODERN PHYSICS by Daniel Bernard Gopman This thesis was prepared under the direction of the candidate’s thesis advisor, Dr. Christopher D. Ely, and has been approved by the members of his supervisory committee. It was submitted to the faculty of The Honors College and was accepted in partial fulfillment of the requirements for the degree of Bachelor of Arts in Liberal Arts and Sciences. THESIS ADVISORY COMMITTEE: _____________________________ Dr. Christopher D. Ely _____________________________ Dr. Daniel R. White _____________________________ Dean, Wilkes Honors College ____________ Date iii Acknowledgments I am deeply grateful for the guidance of my advisor, Dr. Christopher Ely, who kept me focused on a vastly broad, speculative subject. I would also like to express my gratitude to my second advisor, Dr. Daniel White, who introduced me to the great philosophical works on science of the 20th Century. Finally, I want to thank my father, Miles, for the seemingly endless conversations that helped to inspire many of my ideas. iv ABSTRACT Author: Daniel Bernard Gopman Title: Transcendental minds and mythical strings: the emergence of Platonism in modern physics. Institution: Wilkes Honors College of Florida Atlantic University Thesis Advisor: Dr.
    [Show full text]
  • Knocking on Heaven's Door
    Knocking on Heaven’s Door KKnockingHeaven_i_xxiv_1_440_F.inddnockingHeaven_i_xxiv_1_440_F.indd i 77/18/11/18/11 44:31:31 PMPM ALSO BY LISA RANDALL Warped Passages KKnockingHeaven_i_xxiv_1_440_F.inddnockingHeaven_i_xxiv_1_440_F.indd iiii 77/18/11/18/11 44:31:31 PMPM Knocking on Heaven’s Door HOW PHYSICS AND SCIENTIFIC THINKING ILLUMINATE THE UNIVERSE AND THE MODERN WORLD Lisa Randall KKnockingHeaven_i_xxiv_1_440_F.inddnockingHeaven_i_xxiv_1_440_F.indd iiiiii 77/18/11/18/11 44:31:31 PMPM Grateful acknowledgment is made to reprint the following: “Come Together” © 1969 Sony/ATV Music Publishing LLC. All rights administerd by Sony/ATV Music Publishing, LLC, 8 Music Square West, Nashville, TN 37203. All rights reserved. Used by permission. “Jet Song” by Leonard Bernstein and Stephen Sondheim. Copyright © 1956, 1957, 1958, 1959 by Amberson Holdings LLC and Stephen Sondheim. Copyright renewed. Leonard Bernstein Music Publishing Company LLC, publisher. Boosey & Hawkes, agent for rental. International copyright secured. Reprinted by Permission. Every attempt has been made to contact copyright holders. The author and publisher will be happy to make good in future printings any errors or omissions. knocking on heaven’s door. Copyright © 2011 by Lisa Randall. All rights reserved. Printed in the United States of America. No part of this book may be used or repro- duced in any manner whatsoever without written permission except in the case of brief quotations embodied in critical articles and reviews. For information address HarperCollins Publishers, 10 East 53rd Street, New York, NY 10022. HarperCollins books may be purchased for educational, business, or sales promo- tional use. For information please write: Special Markets Department, Harper- Collins Publishers, 10 East 53rd Street, New York, NY 10022.
    [Show full text]
  • Video Interviews with Contemporary Women in Physics and Astronomy Introduction the Videos Compiled Here Include Interviews With
    Video Interviews with Contemporary Women in Physics and Astronomy Introduction The videos compiled here include interviews with and profiles of contemporary women astronomers and physicists. The scope of the interviews extends beyond scientific research to highlight the scientists’ personalities and interests. These first-hand perspectives will enhance any lesson plan. The interviews are organized alphabetically by sponsoring institution. Interviews American Physical Society Interview with Mildred Dresselhaus, Applied Physicist http://www.youtube.com/watch?v=3dVHupKEFuI Duration: 6 minutes, 31 seconds Mildred Dresselhaus is a professor of Electrical Engineering and Physics at MIT. She earned a bachelor’s degree in physics from Hunter College in 1951 before studying at the University of Cambridge on a Fulbright fellowship. She later received a master’s degree from Radcliffe College in 1953 and a PhD from the University of Chicago in 1958. During her interview at the 2013 meeting of the American Physical Society, Dresselhaus addresses her work on carbon nanotubes, the state of physics, physics and politics, and the challenges faced by women in physics. As a professional physicist for over 50 years, she offers interesting insight into the evolution of the discipline. American Physical Society Interview with Nergis Mavalvala, Quantum Astrophysicist http://www.youtube.com/watch?v=V2z_jE6eNIU Duration: 5 minutes, 3 seconds Nergis Mavalvala is an associate professor in the Physics Department at MIT. She received a bachelor’s degree in physics and astronomy from Wellesley College in 1990 and a PhD from MIT in 1997. During her interview at the 2013 meeting of the American Physical Society, Mavalvala explains her research and the importance of diversity in physics.
    [Show full text]
  • Warped Extra Dimensions in the Randall-Sundrum Model and a Simple Implementation in Pythia 8
    Bachelor Thesis Warped Extra Dimensions in the Randall-Sundrum Model and a Simple Implementation in Pythia 8 Jakob Calv´en Experimental High Energy Physics Department of Physics Lund University Supervised by: Else Lytken January 26, 2012 Abstract We explore the theory and phenomenology of spatial extra dimensions in the Randall-Sundrum scenario; a possible extension to the Standard Model. We motivate the need for beyond standard model extensions and show how the original Randall- Sundrum model solves the hierarchy problem of particle physics. We also treat an extension to the Randall-Sundrum model where Standard Model fields live in the extra- dimensional bulk and see how it predicts resonant production of Kaluza-Klein excitations of the gauge bosons. In particular, we discuss Kaluza-Klein excited gluons and their subsequent decay into tt¯ pairs. Furthermore, we test an implementation of the Randall- Sundrum model in Pythia 8 and compare the invariant mass of tt¯ pairs coming from Kaluza-Klein gluons with results in the literature. Contents 1 Introduction 2 1.1 The standard model . 3 2 Extra dimensions 6 2.1 The Kaluza-Klein idea . 7 2.2 Large extra dimensions . 8 2.3 The Randall-Sundrum model . 9 2.3.1 Setup . 9 2.3.2 Warped metric . 10 2.3.3 Solving the hierarchy problem . 11 2.3.4 Bulk Randall-Sundrum . 13 2.4 Concluding remarks . 15 3 Bulk Randall-Sundrum in PYTHIA 8 16 3.1 PYTHIA 8 .................................. 17 3.2 Implementation and parameters . 17 3.3 Simulation and results . 17 3.4 Outlook . 19 4 Summary and conclusions 20 Bibliography .
    [Show full text]