String Theory. Volume 1, Introduction to the Bosonic String
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Stephen Hawking: 'There Are No Black Holes' Notion of an 'Event Horizon', from Which Nothing Can Escape, Is Incompatible with Quantum Theory, Physicist Claims
NATURE | NEWS Stephen Hawking: 'There are no black holes' Notion of an 'event horizon', from which nothing can escape, is incompatible with quantum theory, physicist claims. Zeeya Merali 24 January 2014 Artist's impression VICTOR HABBICK VISIONS/SPL/Getty The defining characteristic of a black hole may have to give, if the two pillars of modern physics — general relativity and quantum theory — are both correct. Most physicists foolhardy enough to write a paper claiming that “there are no black holes” — at least not in the sense we usually imagine — would probably be dismissed as cranks. But when the call to redefine these cosmic crunchers comes from Stephen Hawking, it’s worth taking notice. In a paper posted online, the physicist, based at the University of Cambridge, UK, and one of the creators of modern black-hole theory, does away with the notion of an event horizon, the invisible boundary thought to shroud every black hole, beyond which nothing, not even light, can escape. In its stead, Hawking’s radical proposal is a much more benign “apparent horizon”, “There is no escape from which only temporarily holds matter and energy prisoner before eventually a black hole in classical releasing them, albeit in a more garbled form. theory, but quantum theory enables energy “There is no escape from a black hole in classical theory,” Hawking told Nature. Peter van den Berg/Photoshot and information to Quantum theory, however, “enables energy and information to escape from a escape.” black hole”. A full explanation of the process, the physicist admits, would require a theory that successfully merges gravity with the other fundamental forces of nature. -
Anomalies, Dualities, and Topology of D = 6 N = 1 Superstring Vacua
RU-96-16 NSF-ITP-96-21 CALT-68-2057 IASSNS-HEP-96/53 hep-th/9605184 Anomalies, Dualities, and Topology of D =6 N =1 Superstring Vacua Micha Berkooz,1 Robert G. Leigh,1 Joseph Polchinski,2 John H. Schwarz,3 Nathan Seiberg,1 and Edward Witten4 1Department of Physics, Rutgers University, Piscataway, NJ 08855-0849 2Institute for Theoretical Physics, University of California, Santa Barbara, CA 93106-4030 3California Institute of Technology, Pasadena, CA 91125 4Institute for Advanced Study, Princeton, NJ 08540 Abstract We consider various aspects of compactifications of the Type I/heterotic Spin(32)/Z2 theory on K3. One family of such compactifications in- cludes the standard embedding of the spin connection in the gauge group, and is on the same moduli space as the compactification of arXiv:hep-th/9605184v1 25 May 1996 the heterotic E8 × E8 theory on K3 with instanton numbers (8,16). Another class, which includes an orbifold of the Type I theory re- cently constructed by Gimon and Polchinski and whose field theory limit involves some topological novelties, is on the moduli space of the heterotic E8 × E8 theory on K3 with instanton numbers (12,12). These connections between Spin(32)/Z2 and E8 × E8 models can be demonstrated by T duality, and permit a better understanding of non- perturbative gauge fields in the (12,12) model. In the transformation between Spin(32)/Z2 and E8 × E8 models, the strong/weak coupling duality of the (12,12) E8 × E8 model is mapped to T duality in the Type I theory. The gauge and gravitational anomalies in the Type I theory are canceled by an extension of the Green-Schwarz mechanism. -
Towards a String Dual of SYK Arxiv:2103.03187V1 [Hep-Th] 4 Mar
Towards A String Dual of SYK Akash Goel and Herman Verlinde Department of Physics, Princeton University, Princeton, NJ 08544, USA Abstract: We propose a paradigm for realizing the SYK model within string theory. Using the large N matrix description of c < 1 string theory, we show that the effective theory on a large number Q of FZZT D-branes in (p; 1) minimal string theory takes the form of the disorder averaged SYK model with J p interaction. The SYK fermions represent open strings between the FZZT branes and the ZZ branes that underly the matrix model. The continuum SYK dynamics arises upon taking the large Q limit. We observe several qualitative and quantitative links between the SYK model and (p; q) minimal string theory and propose that the two describe different phases of a single system. We comment on the dual string interpretation of double scaled SYK and on the relevance of our results to the recent discussion of the role of ensemble averaging in holography. arXiv:2103.03187v2 [hep-th] 24 Aug 2021 Contents 1 Introduction2 2 SYK from the Two Matrix Model4 2.1 FZZT-branes in the two matrix model4 2.2 Kontsevich matrix model from FZZT branes6 2.3 SYK matrix model from FZZT branes7 3 Towards the Continuum SYK model8 3.1 Non-commutative SYK8 4 From Minimal Strings to SYK 10 4.1 SYK and the (p; q) spectral curve 11 4.2 FZZT brane correlation function 12 4.3 Minimal String-SYK phase diagram 13 5 SYK as a Non-Critical String 14 6 Conclusion 16 A D-branes in Minimal String Theory 18 A.1 Matrices and the non-commutative torus 23 A.2 Non-commutative SYK 24 A.3 Matrix SYK 26 A.4 Mapping between Matrix SYK and Non-Commutative SYK 27 { 1 { 1 Introduction The SYK model is the prototype of a maximally chaotic quantum system with low energy dynamics given by near-AdS2 gravity. -
Eternal Inflation and Its Implications
IOP PUBLISHING JOURNAL OF PHYSICS A: MATHEMATICAL AND THEORETICAL J. Phys. A: Math. Theor. 40 (2007) 6811–6826 doi:10.1088/1751-8113/40/25/S25 Eternal inflation and its implications Alan H Guth Center for Theoretical Physics, Laboratory for Nuclear Science, and Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA E-mail: [email protected] Received 8 February 2006 Published 6 June 2007 Online at stacks.iop.org/JPhysA/40/6811 Abstract Isummarizetheargumentsthatstronglysuggestthatouruniverseisthe product of inflation. The mechanisms that lead to eternal inflation in both new and chaotic models are described. Although the infinity of pocket universes produced by eternal inflation are unobservable, it is argued that eternal inflation has real consequences in terms of the way that predictions are extracted from theoretical models. The ambiguities in defining probabilities in eternally inflating spacetimes are reviewed, with emphasis on the youngness paradox that results from a synchronous gauge regularization technique. Although inflation is generically eternal into the future, it is not eternal into the past: it can be proven under reasonable assumptions that the inflating region must be incomplete in past directions, so some physics other than inflation is needed to describe the past boundary of the inflating region. PACS numbers: 98.80.cQ, 98.80.Bp, 98.80.Es 1. Introduction: the successes of inflation Since the proposal of the inflationary model some 25 years ago [1–4], inflation has been remarkably successful in explaining many important qualitative and quantitative properties of the universe. In this paper, I will summarize the key successes, and then discuss a number of issues associated with the eternal nature of inflation. -
Pitp Lectures
MIFPA-10-34 PiTP Lectures Katrin Becker1 Department of Physics, Texas A&M University, College Station, TX 77843, USA [email protected] Contents 1 Introduction 2 2 String duality 3 2.1 T-duality and closed bosonic strings .................... 3 2.2 T-duality and open strings ......................... 4 2.3 Buscher rules ................................ 5 3 Low-energy effective actions 5 3.1 Type II theories ............................... 5 3.1.1 Massless bosons ........................... 6 3.1.2 Charges of D-branes ........................ 7 3.1.3 T-duality for type II theories .................... 7 3.1.4 Low-energy effective actions .................... 8 3.2 M-theory ................................... 8 3.2.1 2-derivative action ......................... 8 3.2.2 8-derivative action ......................... 9 3.3 Type IIB and F-theory ........................... 9 3.4 Type I .................................... 13 3.5 SO(32) heterotic string ........................... 13 4 Compactification and moduli 14 4.1 The torus .................................. 14 4.2 Calabi-Yau 3-folds ............................. 16 5 M-theory compactified on Calabi-Yau 4-folds 17 5.1 The supersymmetric flux background ................... 18 5.2 The warp factor ............................... 18 5.3 SUSY breaking solutions .......................... 19 1 These are two lectures dealing with supersymmetry (SUSY) for branes and strings. These lectures are mainly based on ref. [1] which the reader should consult for original references and additional discussions. 1 Introduction To make contact between superstring theory and the real world we have to understand the vacua of the theory. Of particular interest for vacuum construction are, on the one hand, D-branes. These are hyper-planes on which open strings can end. On the world-volume of coincident D-branes, non-abelian gauge fields can exist. -
Duality and the Nature of Quantum Space-Time
Duality and the nature of quantum space-time Sanjaye Ramgoolam Queen Mary, University of London Oxford, January 24, 2009 INTRODUCTION Strings provide a working theory of quantum gravity existing in harmony with particle physics Successes include computations of quantum graviton scattering, new models of beyond-standard-model particle physics based on branes, computation of black hole entropy A powerful new discovery : Duality I An unexpected equivalence between two systems, which a priori look completely unrelated, if not manifest opposites. I Large and Small (T-duality) I Gravitational and non-Gravitational. (Gauge-String duality) Unification and Duality I They are both powerful results of string theory. They allow us to calculate things we could not calculate before. I Unification : We asked for it and found it. We kind of know why it had to be there. I Duality : We didn’t ask for it. We use it. We don’t know what it really means. Unification v/s Duality I Unification has an illustrious history dating back to the days of Maxwell. I Before Maxwell, we thought magnets attracting iron on the one hand and lightning on the other had nothing to do with each other I After Maxwell : Magnets produce B-field. Electric discharge in lightning is caused by E-fields. The coupled equations of both allow fluctuating E, B-fields which transport energy travelling at the speed of light. In fact light is electromagnetic waves. Unification v/s Duality I Einstein tried to unify gravity with quantum phsyics. I String Theory goes a long way. I Computes graviton interaction probablities. -
Super-Higgs in Superspace
Article Super-Higgs in Superspace Gianni Tallarita 1,* and Moritz McGarrie 2 1 Departamento de Ciencias, Facultad de Artes Liberales, Universidad Adolfo Ibáñez, Santiago 7941169, Chile 2 Deutsches Elektronen-Synchrotron, DESY, Notkestrasse 85, 22607 Hamburg, Germany; [email protected] * Correspondence: [email protected] or [email protected] Received: 1 April 2019; Accepted: 10 June 2019; Published: 14 June 2019 Abstract: We determine the effective gravitational couplings in superspace whose components reproduce the supergravity Higgs effect for the constrained Goldstino multiplet. It reproduces the known Gravitino sector while constraining the off-shell completion. We show that these couplings arise by computing them as quantum corrections. This may be useful for phenomenological studies and model-building. We give an example of its application to multiple Goldstini. Keywords: supersymmetry; Goldstino; superspace 1. Introduction The spontaneous breakdown of global supersymmetry generates a massless Goldstino [1,2], which is well described by the Akulov-Volkov (A-V) effective action [3]. When supersymmetry is made local, the Gravitino “eats” the Goldstino of the A-V action to become massive: The super-Higgs mechanism [4,5]. In terms of superfields, the constrained Goldstino multiplet FNL [6–12] is equivalent to the A-V formulation (see also [13–17]). It is, therefore, natural to extend the description of supergravity with this multiplet, in superspace, to one that can reproduce the super-Higgs mechanism. In this paper we address two issues—first we demonstrate how the Gravitino, Goldstino, and multiple Goldstini obtain a mass. Secondly, by using the Spurion analysis, we write down the most minimal set of new terms in superspace that incorporate both supergravity and the Goldstino multiplet in order to reproduce the super-Higgs mechanism of [5,18] at lowest order in M¯ Pl. -
Supersymmetric R4 Actions and Quantum Corrections to Superspace Torsion Constraints
DAMTP-2000-91, NORDITA-2000/87 HE, SPHT-T00/117, hep-th/0010182 SUPERSYMMETRIC R4 ACTIONS AND QUANTUM CORRECTIONS TO SUPERSPACE TORSION CONSTRAINTS K. Peetersa, P. Vanhoveb and A. Westerbergc a CERN, TH-division 1211 Geneva 23, Switzerland b SPHT, Orme des Merisiers, CEA / Saclay, 91191 Gif-sur-Yvette, France c NORDITA, Blegdamsvej 17, DK-2100 Copenhagen Ø, Denmark k.peeters, [email protected], [email protected] We present the supersymmetrisation of the anomaly-related R4 term in eleven dimensions and show that it induces no non-trivial modifications to the on-shell supertranslation algebra and the superspace torsion constraints before inclusion of gauge-field terms.1 1 Higher-derivative corrections and supersymmetry The low-energy supergravity limits of superstring theory as well as D-brane effective actions receive infinite sets of correction terms, proportional to in- 2 creasing powers of α0 = ls and induced by superstring theory massless and massive modes. At present, eleven-dimensional supergravity lacks a corre- sponding microscopic underpinning that could similarly justify the presence of higher-derivative corrections to the classical Cremmer-Julia-Scherk action [1]. Nevertheless, some corrections of this kind are calculable from unitarity argu- ments and super-Ward identities in the massless sector of the theory [2] or by anomaly cancellation arguments [3, 4]. Supersymmetry puts severe constraints on higher-derivative corrections. For example, it forbids the appearance of certain corrections (like, e.g, R3 corrections to supergravity effective actions [5]), and groups terms into var- ious invariants [6–9]. The structure of the invariants that contain anomaly- cancelling terms is of great importance due to the quantum nature of the 1Based on talks given by K.P. -
Introduction to Supersymmetry
Introduction to Supersymmetry Pre-SUSY Summer School Corpus Christi, Texas May 15-18, 2019 Stephen P. Martin Northern Illinois University [email protected] 1 Topics: Why: Motivation for supersymmetry (SUSY) • What: SUSY Lagrangians, SUSY breaking and the Minimal • Supersymmetric Standard Model, superpartner decays Who: Sorry, not covered. • For some more details and a slightly better attempt at proper referencing: A supersymmetry primer, hep-ph/9709356, version 7, January 2016 • TASI 2011 lectures notes: two-component fermion notation and • supersymmetry, arXiv:1205.4076. If you find corrections, please do let me know! 2 Lecture 1: Motivation and Introduction to Supersymmetry Motivation: The Hierarchy Problem • Supermultiplets • Particle content of the Minimal Supersymmetric Standard Model • (MSSM) Need for “soft” breaking of supersymmetry • The Wess-Zumino Model • 3 People have cited many reasons why extensions of the Standard Model might involve supersymmetry (SUSY). Some of them are: A possible cold dark matter particle • A light Higgs boson, M = 125 GeV • h Unification of gauge couplings • Mathematical elegance, beauty • ⋆ “What does that even mean? No such thing!” – Some modern pundits ⋆ “We beg to differ.” – Einstein, Dirac, . However, for me, the single compelling reason is: The Hierarchy Problem • 4 An analogy: Coulomb self-energy correction to the electron’s mass A point-like electron would have an infinite classical electrostatic energy. Instead, suppose the electron is a solid sphere of uniform charge density and radius R. An undergraduate problem gives: 3e2 ∆ECoulomb = 20πǫ0R 2 Interpreting this as a correction ∆me = ∆ECoulomb/c to the electron mass: 15 0.86 10− meters m = m + (1 MeV/c2) × . -
LOCALIZATION and STRING DUALITY 1. Introduction According
LOCALIZATION AND STRING DUALITY KEFENG LIU 1. Introduction According to string theorists, String Theory, as the most promising candidate for the grand unification of all fundamental forces in the nature, should be the final theory of the world, and should be unique. But now there are five different looking string theories. As argued by the physicists, these theories should be equivalent, in a way dual to each other. On the other hand all previous theories like the Yang-Mills and the Chern-Simons theory should be parts of string theory. In particular their partition functions should be equal or equivalent to each other in the sense that they are equal after certain transformation. To compute partition functions, physicists use localization technique, a modern version of residue theorem, on infinite dimen- sional spaces. More precisely they apply localization formally to path integrals which is not well-defined yet in mathematics. In many cases such computations reduce the path integrals to certain integrals of various Chern classes on various finite dimensional moduli spaces, such as the moduli spaces of stable maps and the moduli spaces of vector bundles. The identifications of these partition functions among different theories have produced many surprisingly beautiful mathematical formulas like the famous mirror formula [22], as well as the Mari˜no-Vafa formula [25]. The mathematical proofs of these formulas from the string duality also depend on localization techniques on these various finite dimensional moduli spaces. The purpose of this note is to discuss our recent work on the subject. I will briefly discuss the proof of the Marin˜o-Vafa formula, its generalizations and the related topological vertex theory [1]. -
2000 Annual Report
2001 ANNUAL REPORT ALFRED P. SLOAN FOUNDATION 1 CONTENTS 2001 Grants and Activities Science and Technology 5 Fellowships 5 Sloan Research Fellowships 5 Direct Support of Research 9 Neuroscience 9 Computational Molecular Biology 9 Limits to Knowledge 10 Marine Science 11 Other Science and Science Policy 15 History of Science and Technology 16 Standard of Living and Economic Performance 17 Industries 17 Industry Centers 17 Human Resources/Jobs/Income 21 Globalization 21 Business Organizations 22 Economics Research and Other Work 24 Nonprofit Sectors 26 Universities 26 Assessment of Government Performance 26 Work, Workforce and Working Families 30 Centers on Working Families 30 Workplace Structure and Opportunity 31 Working Families and Everyday Life 34 Education and Careers in Science and Technology 36 Scientific and Technical Careers 36 Anytime, Anyplace Learning 36 Professional Master’s Degrees 42 Information about Careers 47 Entry and Retention 48 Science and Engineering Education 48 Education for Minorities and Women 49 Minorities 49 Women 53 Public Understanding of Science and Technology 55 Books 55 Sloan Technology Book Series 57 Radio 58 2 Public Television 59 Commercial Television and Films 60 Theater 61 General 63 Selected National Issues and The Civic Program 64 Selected National Issues 64 September 11 64 Bioterrorism 66 Energy 68 Federal Statistics 69 Public Policy Research 69 The Civic Program 71 Additional Grants 73 2001 Financial Report Financial Review 75 Auditors’ Report 76 Balance Sheets 77 Statements of Activities 78 Statements of Cash Flows 79 Notes to Financial Statements 80 Schedules of Management and Investment Expenses 83 3 2001 GRANTS AND ACTIVITIES 4 SCIENCE AND TECHNOLOGY FELLOWSHIPS Sloan Research Fellowships $4,160,000 The Sloan Research Fellowship Program aims to stimulate fundamental research by young scholars with outstanding promise to contribute significantly to the advancement of knowledge. -
M-Theory Solutions and Intersecting D-Brane Systems
M-Theory Solutions and Intersecting D-Brane Systems A Thesis Submitted to the College of Graduate Studies and Research in Partial Fulfillment of the Requirements for the degree of Doctor of Philosophy in the Department of Physics and Engineering Physics University of Saskatchewan Saskatoon By Rahim Oraji ©Rahim Oraji, December/2011. All rights reserved. Permission to Use In presenting this thesis in partial fulfilment of the requirements for a Postgrad- uate degree from the University of Saskatchewan, I agree that the Libraries of this University may make it freely available for inspection. I further agree that permission for copying of this thesis in any manner, in whole or in part, for scholarly purposes may be granted by the professor or professors who supervised my thesis work or, in their absence, by the Head of the Department or the Dean of the College in which my thesis work was done. It is understood that any copying or publication or use of this thesis or parts thereof for financial gain shall not be allowed without my written permission. It is also understood that due recognition shall be given to me and to the University of Saskatchewan in any scholarly use which may be made of any material in my thesis. Requests for permission to copy or to make other use of material in this thesis in whole or part should be addressed to: Head of the Department of Physics and Engineering Physics 116 Science Place University of Saskatchewan Saskatoon, Saskatchewan Canada S7N 5E2 i Abstract It is believed that fundamental M-theory in the low-energy limit can be described effectively by D=11 supergravity.