List of Publications Peter Goddard
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Particles-Versus-Strings.Pdf
Particles vs. strings http://insti.physics.sunysb.edu/~siegel/vs.html In light of the huge amount of propaganda and confusion regarding string theory, it might be useful to consider the relative merits of the descriptions of the fundamental constituents of matter as particles or strings. (More-skeptical reviews can be found in my physics parodies.A more technical analysis can be found at "Warren Siegel's research".) Predictability The main problem in high energy theoretical physics today is predictions, especially for quantum gravity and confinement. An important part of predictability is calculability. There are various levels of calculations possible: 1. Existence: proofs of theorems, answers to yes/no questions 2. Qualitative: "hand-waving" results, answers to multiple choice questions 3. Order of magnitude: dimensional analysis arguments, 10? (but beware hidden numbers, like powers of 4π) 4. Constants: generally low-energy results, like ground-state energies 5. Functions: complete results, like scattering probabilities in terms of energy and angle Any but the last level eventually leads to rejection of the theory, although previous levels are acceptable at early stages, as long as progress is encouraging. It is easy to write down the most general theory consistent with special (and for gravity, general) relativity, quantum mechanics, and field theory, but it is too general: The spectrum of particles must be specified, and more coupling constants and varieties of interaction become available as energy increases. The solutions to this problem go by various names -- "unification", "renormalizability", "finiteness", "universality", etc. -- but they are all just different ways to realize the same goal of predictability. -
Ettore Majorana and the Birth of Autoionization
Ettore Majorana and the birth of autoionization E. Arimondo∗,† Charles W. Clark,‡ and W. C. Martin§ National Institute of Standards and Technology Gaithersburg, MD 20899, USA (Dated: May 19, 2009) Abstract In some of the first applications of modern quantum mechanics to the spectroscopy of many-electron atoms, Ettore Majorana solved several outstanding problems by developing the theory of autoionization. Later literature makes only sporadic refer- ences to this accomplishment. After reviewing his work in its contemporary context, we describe subsequent developments in understanding the spectra treated by Ma- jorana, and extensions of his theory to other areas of physics. We find many puzzles concerning the way in which the modern theory of autoionization was developed. ∗ Permanent address: Dipartimento di Fisica E. Fermi, Universit`adi Pisa, Italy †Electronic address: [email protected] ‡Electronic address: [email protected] §Electronic address: [email protected] 1 Contents I.Introduction 2 II.TheState of Atomic Spectroscopy circa 1931 4 A.Observed Spectra 4 B.Theoriesof Unstable Electronic States 6 III.Symmetry Considerations for Doubly-Excited States 7 IV.Analyses of the Observed Double-Excitation Spectra 8 A.Double Excitation in Helium 8 B.TheIncomplete np2 3P Terms in Zinc, Cadmium, and Mercury 9 V.Contemporary and Subsequent Work on Autoionization 12 A.Shenstone’s Contemporary Identification of Autoionization 12 B.Subsequent foundational work on autoionization 13 VI.Continuing Story of P − P0 Spectroscopy for Zinc, Cadmium, and Mercury 14 VII.Continuing Story of Double Excitation in Helium 16 VIII.Autoionization as a pervasive effect in physics 18 Acknowledgments 19 References 19 Figures 22 I. -
Cosmological Test of the Yilmaz Theory of Gravity
Cosmological test of the Yilmaz theory of gravity Michael Ibison Institute for Advanced Studies at Austin 4030 West Braker Lane, Suite 300, Austin, TX 78759, USA Email: [email protected] Abstract. We test the Yilmaz theory of gravitation by working out the corresponding Friedmann- type equations generated by assuming the Friedmann-Robertson-Walker cosmological metrics. In the case that space is flat the theory is consistent only with either a completely empty universe, or with a negative energy vacuum that decays to produce a constant density of matter. In both cases the total energy remains zero at all times, and in the latter case the acceleration of the expansion is always negative. To obtain a more flexible and potentially more realistic cosmology the equation of state relating the pressure and energy density of the matter creation process must be different from the vacuum, as for example is the case in the steady-state models of Gold, Bondi, Hoyle and others. The theory does not support the Cosmological Principle for curved space K ≠ 0 cosmological metrics. PACS numbers: 04.20.-q 98.80.-k 98.80.Jk 1. Introduction Yilmaz has published two versions of his theory of gravitation. The earlier one introduces an auxiliary scalar field ϕ from which is computed the metric tensor [1], this being the version of the theory cited by Tupper in his short review of scalar-tensor theories [2]. Subsequently Yilmaz published a more comprehensive theory in which the auxiliary field is a tensor [3-8]. In the case of a mass singularity, both theories give an ‘exponential metric’ with line element ds22=−exp()2ϕdt −exp(2ϕ)dx2 (1) where ϕ = Gm / r . -
Hep-Th/0011078V1 9 Nov 2000 1 Okspotdi Atb H ..Dp.O Nryudrgrant Under Energy of Dept
CALT-68-2300 CITUSC/00-060 hep-th/0011078 String Theory Origins of Supersymmetry1 John H. Schwarz California Institute of Technology, Pasadena, CA 91125, USA and Caltech-USC Center for Theoretical Physics University of Southern California, Los Angeles, CA 90089, USA Abstract The string theory introduced in early 1971 by Ramond, Neveu, and myself has two-dimensional world-sheet supersymmetry. This theory, developed at about the same time that Golfand and Likhtman constructed the four-dimensional super-Poincar´ealgebra, motivated Wess and Zumino to construct supersymmet- ric field theories in four dimensions. Gliozzi, Scherk, and Olive conjectured the arXiv:hep-th/0011078v1 9 Nov 2000 spacetime supersymmetry of the string theory in 1976, a fact that was proved five years later by Green and myself. Presented at the Conference 30 Years of Supersymmetry 1Work supported in part by the U.S. Dept. of Energy under Grant No. DE-FG03-92-ER40701. 1 S-Matrix Theory, Duality, and the Bootstrap In the late 1960s there were two parallel trends in particle physics. On the one hand, many hadron resonances were discovered, making it quite clear that hadrons are not elementary particles. In fact, they were found, to good approximation, to lie on linear parallel Regge trajectories, which supported the notion that they are composite. Moreover, high energy scattering data displayed Regge asymptotic behavior that could be explained by the extrap- olation of the same Regge trajectories, as well as one with vacuum quantum numbers called the Pomeron. This set of developments was the focus of the S-Matrix Theory community of theorists. -
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. -
Regge Poles and Elementary Particles
Regge poles and elementary particles R J EDEN Cavendish Laboratory, University of Cambridge Contents Page 1. Introduction . 996 1.l. Preliminary remarks . 996 1.2. Units . 997 1.3. Quantum numbers . 998 1.4. Two-body reactions . 998 1.5. Resonances and particles , . 999 1.6. Kinematics of r;N collisions . 1001 1.7. The physical scattering region . 1002 1.8. Cross sections and collision amplitudes . 1003 2. Experimental survey . I 1005 2.1. Total cross sections. 1006 2.2. Phases of forward amplitudes . 1007 2.3. Elastic cross sections (integrated) . 1008 2.4. Differential elastic cross sections . 1009 2.5. Exchange cross sections . 1010 2.6. Backward scattering . 1012 2.7. Polarization and spin parameters . 1013 2.8. Large-angle scattering . 1013 2.9. Quasi-two-body reactions . 1013 2.10. Photoproduction . 1014 2.1 1. Multiparticle production . * 1015 2.12. Inclusive reactions . 1016 3. Theoretical survey . 1017 3.1. Relativistic kinematics for two-body collisions . 1017 3.2. Analyticity and crossing symmetry . 1018 3.3. Dispersion relations . 1020 3.4. Scattering amplitudes and the S matrix . 1020 3.5. Partial wave expansions . 1021 3.6. Resonances and Regge poles . 1022 4. Basic ideas in Regge theory . 1023 4.1. Regge trajectories and sequences of particles . 1023 4.2. Exchanged trajectories and high-energy behaviour . 1025 4.3. Extended partial wave amplitudes and Regge poles . 1027 4.4. Partial wave series and the Sommerfeld-Watson tra.nsform . 1029 4.5. Branch cuts in the angular momentum plane . 1031 5. Applications of Regge pole models . 1032 5.1. Preliminary summary of properties . -
Stanley Mandelstam
I knew very early of Stanley Mandelstam I started physics as a t Prisoner of the s u Mandelstam Triangle I escaped from the Mandelstam Triangle only to be ensnared in Light-Cone Superspace A Note of Personal Gratitude 1971 NAL Visit SuperConformal Theories P. Ramond (with S. Ananth, D. Belyaev, L. Brink and S.-S. Kim) Light-Cone Superspaces N=4 Super Yang-Mills N=8 SuperConformal N=8 SuperGravity and E7(7) N=16 SuperGravity and E8(8) N=8 Light-Cone Superspace houses D=11: N=1 SuperGravity SO(9); F4/SO(9) D=4: N=8 SuperGravity SO(2)x E7(7) D=3: N=16 SuperGravity E8(8) D=2: N=16 Theory E9(9) N=4 Light-Cone Superspace habitat for D=10: N=1 Super Yang-Mills SO(8) D=4: N=4 Super Yang-Mills PSU(2,2|4) D=3: N=8 Super Conformal OSp(2,2|8) 1 i 1 ϕ (y) = 1 A (y) + i θm θn C (y) + 1θm θn θp θq $ ∂+ A¯ (y) + m n mn m n p mnpqq + ¯ ϕ (y) = +∂A (y) + √2θ θ Cmn (y) +12 θ θ θ θ $mnpq ∂ A (y) ∂ √2 √ 12 1 i 1 i m 2 m n p q m n m n p q + i+ +¯ θ χ¯m(y) + √2θ θ θ $mnpq χ (y) ϕ (y) = + A (y) + θ θ Cmn (y) + θ θ θ θ $mnpq ∂ ∂Am(y) 6 m n p q ∂ √2 12 + θ χ¯m(y) + θ θ θ $mnpq χ (y) 1 i m n 1 m n p ∂q+ + ¯ 6 ϕ (y) = A (y) + √θ θ C L(C2y) + Fθorθ maθ θ $lmnpqism∂ A (y) ∂+i m √ 2 m nmnp q12 + θ χ¯m(y) +2 θ θ θ $mnpq χ (y) 1 0 3 ∂+ 6 x± = (x x ) i √2 √ m m n p q 12 0± 3 + + θ χ¯m(y) + θ θ θ $mnpq χ (y) x± = (x x ) ∂ 6 √2 ± Light-Cone Co1ordina0 3tes: 1 0 3 x± = (x x ) ∂± = ( ∂ ∂ ) √2 ± √2 − ± 1 0 3 1 0 3 x± = (x x ) ∂± = ( ∂ ∂ ) 1 0√ 3 ± 1 1 2√2 − ±1 1 2 ∂± = ( ∂ 2∂ ) x = (x + ix ) x = (x ix ) √2 − ± √2 √2 − m m + 1 1 2 1 1 2 1 q+ , q¯+ n =1 i√2δ n ∂ x = 1(x + ix -
Strings, Boundary Fermions and Coincident D-Branes
Strings, boundary fermions and coincident D-branes Linus Wulff Department of Physics Stockholm University Thesis for the degree of Doctor of Philosophy in Theoretical Physics Department of Physics, Stockholm University Sweden c Linus Wulff, Stockholm 2007 ISBN 91-7155-371-1 pp 1-85 Printed in Sweden by Universitetsservice US-AB, Stockholm 2007 Abstract The appearance in string theory of higher-dimensional objects known as D- branes has been a source of much of the interesting developements in the subject during the past ten years. A very interesting phenomenon occurs when several of these D-branes are made to coincide: The abelian gauge theory liv- ing on each brane is enhanced to a non-abelian gauge theory living on the stack of coincident branes. This gives rise to interesting effects like the natural ap- pearance of non-commutative geometry. The theory governing the dynamics of these coincident branes is still poorly understood however and only hints of the underlying structure have been seen. This thesis focuses on an attempt to better this understanding by writing down actions for coincident branes using so-called boundary fermions, orig- inating in considerations of open strings, instead of matrices to describe the non-abelian fields. It is shown that by gauge-fixing and by suitably quantiz- ing these boundary fermions the non-abelian action that is known, the Myers action, can be reproduced. Furthermore it is shown that under natural assump- tions, unlike the Myers action, the action formulated using boundary fermions also posseses kappa-symmetry, the criterion for being the correct supersym- metric action for coincident D-branes. -
Notas De Física CBPF-NF-007/10 February 2010
ISSN 0029-3865 CBPF - CENTRO BRASILEIRO DE PESQUISAS FíSICAS Rio de Janeiro Notas de Física CBPF-NF-007/10 February 2010 A criticaI Iook at 50 years particle theory from the perspective of the crossing property Bert Schroer Ministét"iQ da Ciência e Tecnologia A critical look at 50 years particle theory from the perspective of the crossing property Dedicated to Ivan Todorov on the occasion of his 75th birthday to be published in Foundations of Physics Bert Schroer CBPF, Rua Dr. Xavier Sigaud 150 22290-180 Rio de Janeiro, Brazil and Institut fuer Theoretische Physik der FU Berlin, Germany December 2009 Contents 1 The increasing gap between foundational work and particle theory 2 2 The crossing property and the S-matrix bootstrap approach 7 3 The dual resonance model, superseded phenomenology or progenitor of a new fundamental theory? 15 4 String theory, a TOE or a tower of Babel within particle theory? 21 5 Relation between modular localization and the crossing property 28 6 An exceptional case of localization equivalence: d=1+1 factorizing mod- els 35 7 Resum´e, some personal observations and a somewhat downbeat outlook 39 8 Appendix: a sketch of modular localization 47 8.1 Modular localization of states . 47 8.2 Localized subalgebras . 51 CBPF-NF-007/10 CBPF-NF-007/10 2 Abstract The crossing property, which originated more than 5 decades ago in the after- math of dispersion relations, was the central new concept which opened an S-matrix based line of research in particle theory. Many constructive ideas in particle theory outside perturbative QFT, among them the S-matrix bootstrap program, the dual resonance model and the various stages of string theory have their historical roots in this property. -
Julian Schwinger: Nuclear Physics, the Radiation Laboratory, Renormalized QED, Source Theory, and Beyond
Julian Schwinger: Nuclear Physics, the Radiation Laboratory, Renormalized QED, Source Theory, and Beyond Kimball A. Milton∗ Homer L. Dodge Department of Physics and Astronomy University of Oklahoma, Norman, OK 73019 USA October 9, 2006 Abstract Julian Schwinger’s influence on twentieth century science is pro- found and pervasive. Of course, he is most famous for his renormal- ization theory of quantum electrodynamics, for which he shared the Nobel Prize with Richard Feynman and Sin-itiro Tomonaga. But al- though this triumph was undoubtedly his most heroic work, his legacy lives on chiefly through subtle and elegant work in classical electrody- namics, quantum variational principles, proper-time methods, quan- tum anomalies, dynamical mass generation, partial symmetry, and more. Starting as just a boy, he rapidly became the pre-eminent nu- clear physicist in the late 1930s, led the theoretical development of radar technology at MIT during World War II, and then, soon after the war, conquered quantum electrodynamics, and became the leading quantum field theorist for two decades, before taking a more icono- clastic route during his last quarter century. Keywords: Julian Schwinger, nuclear physics, waveguides, quan- tum electrodynamics, renormalization, quantum action principle, source theory, axial-vector anomaly ∗K.A. Milton is Professor of Physics at the University of Oklahoma. He was a Ph.D. stu- dent of Julian Schwinger from 1968–71, and his postdoc at UCLA for the rest of the 1970s. He has written a scientific biography of Schwinger, edited two volumes of Schwinger’s se- lected works, and co-authored two textbooks based on Schwinger’s lectures. -
The Early Years of String Theory: a Personal Perspective
CALT-68-2657 THE EARLY YEARS OF STRING THEORY: A PERSONAL PERSPECTIVE John H. Schwarz California Institute of Technology Pasadena, CA 91125, USA Abstract arXiv:0708.1917v3 [hep-th] 3 Apr 2009 This article surveys some of the highlights in the development of string theory through the first superstring revolution in 1984. The emphasis is on topics in which the author was involved, especially the observation that critical string theories provide consistent quantum theories of gravity and the proposal to use string theory to construct a unified theory of all fundamental particles and forces. Based on a lecture presented on June 20, 2007 at the Galileo Galilei Institute 1 Introduction I am happy to have this opportunity to reminisce about the origins and development of string theory from 1962 (when I entered graduate school) through the first superstring revolution in 1984. Some of the topics were discussed previously in three papers that were written for various special events in 2000 [1, 2, 3]. Also, some of this material was reviewed in the 1985 reprint volumes [4], as well as the string theory textbooks [5, 6]. In presenting my experiences and impressions of this period, it is inevitable that my own contributions are emphasized. Some of the other early contributors to string theory have presented their recollections at the Galileo Galilei Institute meeting on “The Birth of String Theory” in May 2007. Since I was unable to attend that meeting, my talk was given at the GGI one month later. Taken together, the papers in this collection should -
![Arxiv:1909.05177V2 [Hep-Th] 16 Jan 2020 3 Regge Theory 20 3.1 the Regge Limit 20 3.2 Complex Angular Momentum 22 3.3 Regge Poles 25](https://docslib.b-cdn.net/cover/4548/arxiv-1909-05177v2-hep-th-16-jan-2020-3-regge-theory-20-3-1-the-regge-limit-20-3-2-complex-angular-momentum-22-3-3-regge-poles-25-1394548.webp)
Arxiv:1909.05177V2 [Hep-Th] 16 Jan 2020 3 Regge Theory 20 3.1 the Regge Limit 20 3.2 Complex Angular Momentum 22 3.3 Regge Poles 25
SciPost Physics Lecture Notes Submission QMUL-PH-19-25 Aspects of High Energy Scattering C. D. White1* 1 Centre for Research in String Theory, School of Physics and Astronomy, Queen Mary University of London, 327 Mile End Road, London E1 4NS, UK * [email protected] January 17, 2020 Abstract Scattering amplitudes in quantum field theories are of widespread interest, due to a large number of theoretical and phenomenological applications. Much is known about the possible behaviour of amplitudes, that is independent of the details of the underlying theory. This knowledge is often neglected in modern QFT courses, and the aim of these notes - aimed at graduate students - is to redress this. We review the possible singularities that amplitudes can have, before examining the generic behaviour that can arise in the high-energy limit. Finally, we illustrate the results using examples from QCD and gravity. Contents 1 Motivation 2 2 Scattering and the S-matrix 3 2.1 The S-matrix 3 2.2 Properties of the S-matrix 6 2.3 Analyticity 9 2.4 Physical regions and crossing 16 arXiv:1909.05177v2 [hep-th] 16 Jan 2020 3 Regge Theory 20 3.1 The Regge limit 20 3.2 Complex angular momentum 22 3.3 Regge poles 25 4 Examples in QCD and gravity 28 4.1 High energy scattering in QCD 28 4.2 High energy scattering in gravity 32 References 34 1 SciPost Physics Lecture Notes Submission 1 Motivation Much research in contemporary theoretical high energy physics involves scattering amplitudes (see e.g. refs. [1, 2] for recent reviews), which are themselves related to the probabilities for interactions between various objects to occur.