Deciphering the Algebraic CPT Theorem
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Perturbative Versus Non-Perturbative Quantum Field Theory: Tao’S Method, the Casimir Effect, and Interacting Wightman Theories
universe Review Perturbative versus Non-Perturbative Quantum Field Theory: Tao’s Method, the Casimir Effect, and Interacting Wightman Theories Walter Felipe Wreszinski Instituto de Física, Universidade de São Paulo, São Paulo 05508-090, SP, Brazil; [email protected] Abstract: We dwell upon certain points concerning the meaning of quantum field theory: the problems with the perturbative approach, and the question raised by ’t Hooft of the existence of the theory in a well-defined (rigorous) mathematical sense, as well as some of the few existent mathematically precise results on fully quantized field theories. Emphasis is brought on how the mathematical contributions help to elucidate or illuminate certain conceptual aspects of the theory when applied to real physical phenomena, in particular, the singular nature of quantum fields. In a first part, we present a comprehensive review of divergent versus asymptotic series, with qed as background example, as well as a method due to Terence Tao which conveys mathematical sense to divergent series. In a second part, we apply Tao’s method to the Casimir effect in its simplest form, consisting of perfectly conducting parallel plates, arguing that the usual theory, which makes use of the Euler-MacLaurin formula, still contains a residual infinity, which is eliminated in our approach. In the third part, we revisit the general theory of nonperturbative quantum fields, in the form of newly proposed (with Christian Jaekel) Wightman axioms for interacting field theories, with applications to “dressed” electrons in a theory with massless particles (such as qed), as well as Citation: Wreszinski, W.F. unstable particles. Various problems (mostly open) are finally discussed in connection with concrete Perturbative versus Non-Perturbative models. -
Renormalisation Circumvents Haag's Theorem
Some no-go results & canonical quantum fields Axiomatics & Haag's theorem Renormalisation bypasses Haag's theorem Renormalisation circumvents Haag's theorem Lutz Klaczynski, HU Berlin Theory seminar DESY Zeuthen, 31.03.2016 Lutz Klaczynski, HU Berlin Renormalisation circumvents Haag's theorem Some no-go results & canonical quantum fields Axiomatics & Haag's theorem Renormalisation bypasses Haag's theorem Outline 1 Some no-go results & canonical quantum fields Sharp-spacetime quantum fields Interaction picture Theorems by Powers & Baumann (CCR/CAR) Schrader's result 2 Axiomatics & Haag's theorem Wightman axioms Haag vs. Gell-Mann & Low Haag's theorem for nontrivial spin 3 Renormalisation bypasses Haag's theorem Renormalisation Mass shift wrecks unitary equivalence Conclusion Lutz Klaczynski, HU Berlin Renormalisation circumvents Haag's theorem Sharp-spacetime quantum fields Some no-go results & canonical quantum fields Interaction picture Axiomatics & Haag's theorem Theorems by Powers & Baumann (CCR/CAR) Renormalisation bypasses Haag's theorem Schrader's result The quest for understanding canonical quantum fields 1 1 Constructive approaches by Glimm & Jaffe : d ≤ 3 2 2 Axiomatic quantum field theory by Wightman & G˚arding : axioms to construe quantum fields in terms of operator theory hard work, some results (eg PCT, spin-statistics theorem) interesting: triviality results (no-go theorems) 3 other axiomatic approaches, eg algebraic quantum field theory General form of no-go theorems φ quantum field with properties so-and-so ) φ is trivial. 3 forms -
275 – Quantum Field Theory
Quantum eld theory Lectures by Richard Borcherds, notes by Søren Fuglede Jørgensen Math 275, UC Berkeley, Fall 2010 Contents 1 Introduction 1 1.1 Dening a QFT . 1 1.2 Constructing a QFT . 2 1.3 Feynman diagrams . 4 1.4 Renormalization . 4 1.5 Constructing an interacting theory . 6 1.6 Anomalies . 6 1.7 Infrared divergences . 6 1.8 Summary of problems and solutions . 7 2 Review of Wightman axioms for a QFT 7 2.1 Free eld theories . 8 2.2 Fixing the Wightman axioms . 10 2.2.1 Reformulation in terms of distributions and states . 10 2.2.2 Extension of the Wightman axioms . 12 2.3 Free eld theory revisited . 12 2.4 Propagators . 13 2.5 Review of properties of distributions . 13 2.6 Construction of a massive propagator . 14 2.7 Wave front sets . 17 Disclaimer These are notes from the rst 4 weeks of a course given by Richard Borcherds in 2010.1 They are discontinued from the 7th lecture due to time constraints. They have been written and TeX'ed during the lecture and some parts have not been completely proofread, so there's bound to be a number of typos and mistakes that should be attributed to me rather than the lecturer. Also, I've made these notes primarily to be able to look back on what happened with more ease, and to get experience with TeX'ing live. That being said, feel very free to send any comments and or corrections to [email protected]. 1st lecture, August 26th 2010 1 Introduction 1.1 Dening a QFT The aim of the course is to dene a quantum eld theory, to nd out what a quantum eld theory is, and to dene Feynman measures, renormalization, anomalies, and regularization. -
The Renormalization Group in Quantum Field Theory
COARSE-GRAINING AS A ROUTE TO MICROSCOPIC PHYSICS: THE RENORMALIZATION GROUP IN QUANTUM FIELD THEORY BIHUI LI DEPARTMENT OF HISTORY AND PHILOSOPHY OF SCIENCE UNIVERSITY OF PITTSBURGH [email protected] ABSTRACT. The renormalization group (RG) has been characterized as merely a coarse-graining procedure that does not illuminate the microscopic content of quantum field theory (QFT), but merely gets us from that content, as given by axiomatic QFT, to macroscopic predictions. I argue that in the constructive field theory tradition, RG techniques do illuminate the microscopic dynamics of a QFT, which are not automatically given by axiomatic QFT. RG techniques in constructive field theory are also rigorous, so one cannot object to their foundational import on grounds of lack of rigor. Date: May 29, 2015. 1 Copyright Philosophy of Science 2015 Preprint (not copyedited or formatted) Please use DOI when citing or quoting 1. INTRODUCTION The renormalization group (RG) in quantum field theory (QFT) has received some attention from philosophers for how it relates physics at different scales and how it makes sense of perturbative renormalization (Huggett and Weingard 1995; Bain 2013). However, it has been relatively neglected by philosophers working in the axiomatic QFT tradition, who take axiomatic QFT to be the best vehicle for interpreting QFT. Doreen Fraser (2011) has argued that the RG is merely a way of getting from the microscopic principles of QFT, as provided by axiomatic QFT, to macroscopic experimental predictions. Thus, she argues, RG techniques do not illuminate the theoretical content of QFT, and we should stick to interpreting axiomatic QFT. David Wallace (2011), in contrast, has argued that the RG supports an effective field theory (EFT) interpretation of QFT, in which QFT does not apply to arbitrarily small length scales. -
CPT Theorem and Classification of Topological Insulators And
CPT theorem and classification of topological insulators and superconductors Chang-Tse Hsieh,1 Takahiro Morimoto,2 and Shinsei Ryu1 1Department of Physics, University of Illinois at Urbana-Champaign, 1110 West Green St, Urbana IL 61801 2Condensed Matter Theory Laboratory, RIKEN, Wako, Saitama, 351-0198, Japan (ΩDated: June 3, 2014) We present a systematic topological classification of fermionic and bosonic topological phases protected by time-reversal, particle-hole, parity, and combination of these symmetries. We use two complementary approaches: one in terms of K-theory classification of gapped quadratic fermion theories with symmetries, and the other in terms of the K-matrix theory description of the edge theory of (2+1)-dimensional bulk theories. The first approach is specific to free fermion theories in general spatial dimensions while the second approach is limited to two spatial dimensions but incorporates effects of interactions. We also clarify the role of CPT theorem in classification of symmetry-protected topological phases, and show, in particular, topological superconductors dis- cussed before are related by CPT theorem. CONTENTS VI. Discussion 19 I. Introduction 1 Acknowledgments 19 A. Outline and main results 3 A. Entanglement spectrum and effective symmetries 19 II. 2D fermionic topological phases protected by 1.Entanglementspectrum 20 symmetries 4 2. Properties of entanglement spectrum with A. CP symmetric insulators 4 symmetries 21 1. tight-binding model 4 2.Edgetheory 5 B. Calculations of symmetry transformations and B. BdG systems with spin U(1) and P SPT phases in K-matrix theories 21 symmetries 5 1. Algebraic relations of symmetry operators 21 C. Connection to T symmetric insulators 6 2. -
CPT, Lorentz Invariance, Mass Differences, and Charge Non
CPT, Lorentz invariance, mass differences, and charge non-conservation A.D. Dolgova,b,c,d, V.A. Novikova,b September 11, 2018 a Novosibirsk State University, Novosibirsk, 630090, Russia b Institute of Theoretical and Experimental Physics, Moscow, 113259, Russia cDipartimento di Fisica, Universit`adegli Studi di Ferrara, I-44100 Ferrara, Italy dIstituto Nazionale di Fisica Nucleare, Sezione di Ferrara, I-44100 Ferrara, Italy Abstract A non-local field theory which breaks discrete symmetries, including C, P, CP, and CPT, but preserves Lorentz symmetry, is presented. We demonstrate that at one-loop level the masses for particle and antiparticle remain equal due to Lorentz symmetry only. An inequality of masses implies breaking of the Lorentz invariance and non-conservation of the usually conserved charges. arXiv:1204.5612v1 [hep-ph] 25 Apr 2012 1 1 Introduction The interplay of Lorentz symmetry and CPT symmetry was considered in the literature for decades. The issue attracted an additional interest recently due to a CPT-violating sce- nario in neutrino physics with different mass spectrum of neutrinos and antineutrinos [1]. Theoretical frameworks of CPT breaking in quantum field theories, in fact in string theo- ries, and detailed phenomenology of oscillating neutrinos with different masses of ν andν ¯ was further studied in papers [2]. On the other hand, it was argued in ref. [3] that violation of CPT automatically leads to violation of the Lorentz symmetry [3]. This might allow for some more freedom in phenomenology of neutrino oscillations. Very recently this conclusion was revisited in our paper [4]. We demonstrated that field theories with different masses for particle and antiparticle are extremely pathological ones and can’t be treated as healthy quantum field theories. -
CPT Symmetry, Quantum Gravity and Entangled Neutral Kaons Antonio Di Domenico Dipartimento Di Fisica, Sapienza Università Di Roma and INFN Sezione Di Roma, Italy
CPT symmetry, Quantum Gravity and entangled neutral kaons Antonio Di Domenico Dipartimento di Fisica, Sapienza Università di Roma and INFN sezione di Roma, Italy Fourteenth Marcel Grossmann Meeting - MG14 University of Rome "La Sapienza" - Rome, July 12-18, 2015 MG Meetings News MG Meetings News Scientific Objectives Press releases The Previous Registration Meetings Internet connections Satellite meetings MG Awards MG14 Booklet MG14 Summary The MG Awards Important dates Previous MG Awards Location Publications Public Lectures Click to download the preliminary poster Titles & Abstracts Social Events Proceedings Accompanying Secretariat/registration open from 8:00am to 1:30pm from wednesday Persons Activities Payment of registration fee after Wednesday 1pm o'clock will be General Information possible only by cash Photos Information about We thank ICTP, INFN, IUPAP, NSF for their support! Rome Scientific Committees Live streaming of Plenary and Public Lectures Transportation International photos of the meeting available here Meals Organizing Hotels Local Organizing International Organizing Committee chair: Remo Ruffini, University of Rome and ICRANet Participants International International Coordinating Committee chair: Robert Jantzen, Villanova University Coordination Local Organizing Committee chair: Massimo Bianchi, University of Rome "Tor Vergata" Preliminary List Scientific Program The Fourteenth Marcel Grossmann Meeting on Recent Developments in Theoretical and Experimental General Contacts Relativity, Gravitation, and Relativistic Field Theory will take place at the University of Rome Sapienza July 12 - 18, Plenary Invited Contact us Speakers 2015, celebrating the 100th anniversary of the Einstein equations as well as the International Year of Light under the aegis of the United Nations. Plenary Program Links For the first time, in addition to the main meeting in Rome, a series of satellite meetings to MG14 will take place. -
Quantum Field Theory a Tourist Guide for Mathematicians
Mathematical Surveys and Monographs Volume 149 Quantum Field Theory A Tourist Guide for Mathematicians Gerald B. Folland American Mathematical Society http://dx.doi.org/10.1090/surv/149 Mathematical Surveys and Monographs Volume 149 Quantum Field Theory A Tourist Guide for Mathematicians Gerald B. Folland American Mathematical Society Providence, Rhode Island EDITORIAL COMMITTEE Jerry L. Bona Michael G. Eastwood Ralph L. Cohen Benjamin Sudakov J. T. Stafford, Chair 2010 Mathematics Subject Classification. Primary 81-01; Secondary 81T13, 81T15, 81U20, 81V10. For additional information and updates on this book, visit www.ams.org/bookpages/surv-149 Library of Congress Cataloging-in-Publication Data Folland, G. B. Quantum field theory : a tourist guide for mathematicians / Gerald B. Folland. p. cm. — (Mathematical surveys and monographs ; v. 149) Includes bibliographical references and index. ISBN 978-0-8218-4705-3 (alk. paper) 1. Quantum electrodynamics–Mathematics. 2. Quantum field theory–Mathematics. I. Title. QC680.F65 2008 530.1430151—dc22 2008021019 Copying and reprinting. Individual readers of this publication, and nonprofit libraries acting for them, are permitted to make fair use of the material, such as to copy a chapter for use in teaching or research. Permission is granted to quote brief passages from this publication in reviews, provided the customary acknowledgment of the source is given. Republication, systematic copying, or multiple reproduction of any material in this publication is permitted only under license from the American Mathematical Society. Requests for such permission should be addressed to the Acquisitions Department, American Mathematical Society, 201 Charles Street, Providence, Rhode Island 02904-2294 USA. Requests can also be made by e-mail to [email protected]. -
An Introduction to Rigorous Formulations of Quantum Field Theory
An introduction to rigorous formulations of quantum field theory Daniel Ranard Perimeter Institute for Theoretical Physics Advisors: Ryszard Kostecki and Lucien Hardy May 2015 Abstract No robust mathematical formalism exists for nonperturbative quantum field theory. However, the attempt to rigorously formulate field theory may help one understand its structure. Multiple approaches to axiomatization are discussed, with an emphasis on the different conceptual pictures that inspire each approach. 1 Contents 1 Introduction 3 1.1 Personal perspective . 3 1.2 Goals and outline . 3 2 Sketches of quantum field theory 4 2.1 Locality through tensor products . 4 2.2 Schr¨odinger(wavefunctional) representation . 6 2.3 Poincar´einvariance and microcausality . 9 2.4 Experimental predictions . 12 2.5 Path integral picture . 13 2.6 Particles and the Fock space . 17 2.7 Localized particles . 19 3 Seeking rigor 21 3.1 Hilbert spaces . 21 3.2 Fock space . 23 3.3 Smeared fields . 23 3.4 From Hilbert space to algebra . 25 3.5 Euclidean path integral . 30 4 Axioms for quantum field theory 31 4.1 Wightman axioms . 32 4.2 Haag-Kastler axioms . 32 4.3 Osterwalder-Schrader axioms . 33 4.4 Consequences of the axioms . 34 5 Outlook 35 6 Acknowledgments 35 2 1 Introduction 1.1 Personal perspective What is quantum field theory? Rather than ask how nature truly acts, simply ask: what is this theory? For a moment, strip the physical theory of its interpretation. What remains is the abstract mathematical arena in which one performs calculations. The theory of general relativity becomes geometry on a Lorentzian manifold; quantum theory becomes the analysis of Hilbert spaces and self-adjoint operators. -
Quantum Tests of the Einstein Equivalence Principle with the STE- QUEST Space Mission
Publications 1-2015 Quantum Tests of the Einstein Equivalence Principle with the STE- QUEST Space Mission Brett Altschul University of South Carolina Quentin G. Bailey Embry-Riddle Aeronautical University, [email protected] Luc Blanchet Kai Bongs Philippe Bouyer See next page for additional authors Follow this and additional works at: https://commons.erau.edu/publication Part of the Cosmology, Relativity, and Gravity Commons Scholarly Commons Citation Altschul, B., Bailey, Q. G., Blanchet, L., Bongs, K., Bouyer, P., Cacciapuoti, L., & al., e. (2015). Quantum Tests of the Einstein Equivalence Principle with the STE-QUEST Space Mission. Advances in Space Research, 55(1). https://doi.org/10.1016/j.asr.2014.07.014 This Article is brought to you for free and open access by Scholarly Commons. It has been accepted for inclusion in Publications by an authorized administrator of Scholarly Commons. For more information, please contact [email protected]. Authors Brett Altschul, Quentin G. Bailey, Luc Blanchet, Kai Bongs, Philippe Bouyer, Luigi Cacciapuoti, and et al. This article is available at Scholarly Commons: https://commons.erau.edu/publication/614 Quantum Tests of the Einstein Equivalence Principle with the STE-QUEST Space Mission Brett Altschul,1 Quentin G. Bailey,2 Luc Blanchet,3 Kai Bongs,4 Philippe Bouyer,5 Luigi Cacciapuoti,6 Salvatore Capozziello,7, 8, 9 Naceur Gaaloul,10 Domenico Giulini,11, 12 Jonas Hartwig,10 Luciano Iess,13 Philippe Jetzer,14 Arnaud Landragin,15 Ernst Rasel,10 Serge Reynaud,16 Stephan Schiller,17 Christian Schubert,10 -
CPT Symmetry and Properties of the Exact and Approximate Effective
Proceedings of Institute of Mathematics of NAS of Ukraine 2004, Vol. 50, Part 2, 973–980 CPT Symmetry and Properties of the Exact and Approximate Effective Hamiltonians for the Neutral Kaon Complex1 Krzysztof URBANOWSKI University of Zielona G´ora, Institute of Physics, ul. Podg´orna 50, 65-246 Zielona G´ora, Poland E-mail: [email protected], [email protected] We show that the diagonal matrix elements of the exact effective Hamiltonian governing the time evolution in the subspace of states of an unstable particle and its antiparticle need not be equal at for t>t0 (t0 is the instant of creation of the pair) when the total system under consideration is CPT invariant but CP noninvariant. The unusual consequence of this result is that, contrary to the properties of stable particles, the masses of the unstable particle “1” and its antiparticle “2” need not be equal for t t0 in the case of preserved CPT and violated CP symmetries. 1 Introduction The problem of testing CPT-invariance experimentally has attracted the attention of physicist, practically since the discovery of antiparticles. CPT symmetry is a fundamental theorem of axiomatic quantum field theory which follows from locality, Lorentz invariance, and unitarity [2]. Many tests of CPT-invariance consist in searching for decay process of neutral kaons. All known CP- and hypothetically possible CPT-violation effects in neutral kaon complex are described by solving the Schr¨odinger-like evolution equation [3–7] (we use = c = 1 units) ∂ i |ψ t H |ψ t ∂t ; = ; (1) for |ψ; t belonging to the subspace H ⊂H(where H is the state space of the physical system under investigation), e.g., spanned by orthonormal neutral kaons states |K0, |K0,and def so on, (then states corresponding with the decay products belong to HH = H⊥), and non-Hermitian effective Hamiltonian H obtained usually by means of Lee–Oehme–Yang (LOY) approach (within the Weisskopf–Wigner approximation (WW)) [3–5, 7]: i H ≡ M − Γ, (2) 2 where M = M +,Γ=Γ+,are(2× 2) matrices. -
Ed Nelson's Work in Quantum Theory 1
ED NELSON’S WORK IN QUANTUM THEORY BARRY SIMON¤ Abstract. We review Edward Nelson’s contributions to nonrel- ativistic quantum theory and to quantum field theory. 1. Introduction It is a pleasure to contribute to this celebration of Ed Nelson’s scien- tific work, not only because of the importance of that work but because it allows me an opportunity to express my gratitude and acknowledge my enormous debt to Ed. He and Arthur Wightman were the key for- mulative influences on my education, not only as a graduate student but during my early postdoctoral years. Thanks, Ed! I was initially asked to talk about Ed’s work in quantum field theory (QFT), but I’m going to exceed my assignment by also discussing Ed’s impact on conventional nonrelativistic quantum mechanics (NRQM). There will be other talks on his work on unconventional quantum the- ory. After discussion of NRQM and the Nelson model, I’ll turn to the truly great contributions: the first control of a renormalization, albeit the Wick ordering that is now regarded as easy, and the seminal work on Euclidean QFT. Many important ideas I’ll discuss below involve crucial remarks of Ed that — in his typically generous fashion — he allowed others to publish. 2. NRQM Ed has very little published specifically on conventional NRQM but he had substantial impact through his lectures, students, and ideas from his papers that motivated work on NRQM. In particular, two of Date: August 12, 2004. ¤ Mathematics 253-37, California Institute of Technology, Pasadena, CA 91125, USA. E-mail: [email protected].