Division Algebras, Supersymmetry and Higher Gauge Theory
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Introduction to Supersymmetry(1)
Introduction to Supersymmetry(1) J.N. Tavares Dep. Matem¶aticaPura, Faculdade de Ci^encias,U. Porto, 4000 Porto TQFT Club 1Esta ¶euma vers~aoprovis¶oria,incompleta, para uso exclusivo nas sess~oesde trabalho do TQFT club CONTENTS 1 Contents 1 Supersymmetry in Quantum Mechanics 2 1.1 The Supersymmetric Oscillator . 2 1.2 Witten Index . 4 1.3 A fundamental example: The Laplacian on forms . 7 1.4 Witten's proof of Morse Inequalities . 8 2 Supergeometry and Supersymmetry 13 2.1 Field Theory. A quick review . 13 2.2 SuperEuclidean Space . 17 2.3 Reality Conditions . 18 2.4 Supersmooth functions . 18 2.5 Supermanifolds . 21 2.6 Lie Superalgebras . 21 2.7 Super Lie groups . 26 2.8 Rigid Superspace . 27 2.9 Covariant Derivatives . 30 3 APPENDIX. Cli®ord Algebras and Spin Groups 31 3.1 Cli®ord Algebras . 31 Motivation. Cli®ord maps . 31 Cli®ord Algebras . 33 Involutions in V .................................. 35 Representations . 36 3.2 Pin and Spin groups . 43 3.3 Spin Representations . 47 3.4 U(2), spinors and almost complex structures . 49 3.5 Spinc(4)...................................... 50 Chiral Operator. Self Duality . 51 2 1 Supersymmetry in Quantum Mechanics 1.1 The Supersymmetric Oscillator i As we will see later the \hermitian supercharges" Q®, in the N extended SuperPoincar¶eLie Algebra obey the anticommutation relations: i j m ij fQ®;Q¯g = 2(γ C)®¯± Pm (1.1) m where ®; ¯ are \spinor" indices, i; j 2 f1; ¢ ¢ ¢ ;Ng \internal" indices and (γ C)®¯ a bilinear form in the spinor indices ®; ¯. When specialized to 0-space dimensions ((1+0)-spacetime), then since P0 = H, relations (1.1) take the form (with a little change in notations): fQi;Qjg = 2±ij H (1.2) with N \Hermitian charges" Qi; i = 1; ¢ ¢ ¢ ;N. -
Conformal Killing Superalgebras
CONFORMAL SYMMETRY SUPERALGEBRAS PAUL DE MEDEIROS AND STEFAN HOLLANDS ABSTRACT. We show how the rigid conformal supersymmetries associated with a certain class of pseudo-Riemannian spin manifolds define a Lie superalgebra. The even part of this superalgebra con- tains conformal isometries and constant R-symmetries. The odd part is generated by twistor spinors valued in a particular R-symmetry representation. We prove that any manifold which admits a con- formal symmetry superalgebra of this type must generically have dimension less than seven. Moreover, in dimensions three, four, five and six, we provide the generic data from which the conformal symmetry superalgebra is prescribed. For conformally flat metrics in these dimensions, and compact R-symmetry, we identify each of the associated conformal symmetry superalgebras with one of the conformal su- peralgebras classified by Nahm. We also describe several examples for Lorentzian metrics that are not conformally flat. CONTENTS 1. Introduction 2 2. Preliminaries 3 2.1. Tensors, vectors and conformal Killing vectors 3 2.2. Clifford modules, spinors and twistor spinors 4 3. Conformal structure 6 4. Spinorial bilinear forms 6 4.1. Complex case 8 4.2. Real case 9 5. Conformal symmetry superalgebras 10 5.1. Brackets 10 5.2. Conformal invariance 11 5.3. Jacobi identities 12 5.4. Real forms 12 6. Comparison with Nahm for conformally flat metrics 14 7. Some non-trivial examples in Lorentzian signature 15 arXiv:1302.7269v2 [hep-th] 3 Jun 2013 7.1. Brinkmann waves 16 7.2. Lorentzian Einstein-Sasaki manifolds 17 7.3. Fefferman spaces 17 7.4. Direct products 18 Acknowledgments 19 References 19 Date: 9th October 2018. -
Arxiv:1905.09269V2
Anomaly cancellation in the topological string Kevin Costello∗ Perimeter Institute of Theoretical Physics 31 Caroline St N, Waterloo, ON N2L 2Y5, Canada Si Li† Department of Mathematical Sciences and Yau Mathematical Sciences Center, Jingzhai, Tsinghua University, Beijing 100084, China (Dated: January 7, 2020) We describe the coupling of holomorphic Chern-Simons theory at large N with Kodaira- Spencer gravity. We explain a new anomaly cancellation mechanism at all loops in pertur- bation theory for open-closed topological B-model. At one loop this anomaly cancellation is analogous to the Green-Schwarz mechanism. As an application, we introduce a type I version of Kodaira-Spencer theory in complex dimensions 3 and 5. In complex dimension 5, we show that it can only be coupled consistently at the quantum level to holomorphic Chern-Simons theory with gauge group SO(32). This is analogous to the Green-Schwarz mechanism for the physical type I string. This coupled system is conjectured to be a supersymmetric localization of type I string theory. In complex dimension 3, the required gauge group is SO(8). Contents I. Introduction 2 II. Open-closed topological B-model 3 A. The open-string sector 3 arXiv:1905.09269v2 [hep-th] 5 Jan 2020 B. The closed-string sector 6 C. Coupling closed to open strings at leading order 8 D. Kodaira-Spencer gravity in BV formalism 9 E. Green-Schwarz mechanism 13 F. The holomorphic stress-energy tensors 15 ∗Electronic address: [email protected] †Electronic address: [email protected] 2 G. Large N single trace operators 19 H. -
Effective Field Theories, Reductionism and Scientific Explanation Stephan
To appear in: Studies in History and Philosophy of Modern Physics Effective Field Theories, Reductionism and Scientific Explanation Stephan Hartmann∗ Abstract Effective field theories have been a very popular tool in quantum physics for almost two decades. And there are good reasons for this. I will argue that effec- tive field theories share many of the advantages of both fundamental theories and phenomenological models, while avoiding their respective shortcomings. They are, for example, flexible enough to cover a wide range of phenomena, and concrete enough to provide a detailed story of the specific mechanisms at work at a given energy scale. So will all of physics eventually converge on effective field theories? This paper argues that good scientific research can be characterised by a fruitful interaction between fundamental theories, phenomenological models and effective field theories. All of them have their appropriate functions in the research process, and all of them are indispens- able. They complement each other and hang together in a coherent way which I shall characterise in some detail. To illustrate all this I will present a case study from nuclear and particle physics. The resulting view about scientific theorising is inherently pluralistic, and has implications for the debates about reductionism and scientific explanation. Keywords: Effective Field Theory; Quantum Field Theory; Renormalisation; Reductionism; Explanation; Pluralism. ∗Center for Philosophy of Science, University of Pittsburgh, 817 Cathedral of Learning, Pitts- burgh, PA 15260, USA (e-mail: [email protected]) (correspondence address); and Sektion Physik, Universit¨at M¨unchen, Theresienstr. 37, 80333 M¨unchen, Germany. 1 1 Introduction There is little doubt that effective field theories are nowadays a very popular tool in quantum physics. -
Casimir Effect on the Lattice: U (1) Gauge Theory in Two Spatial Dimensions
Casimir effect on the lattice: U(1) gauge theory in two spatial dimensions M. N. Chernodub,1, 2, 3 V. A. Goy,4, 2 and A. V. Molochkov2 1Laboratoire de Math´ematiques et Physique Th´eoriqueUMR 7350, Universit´ede Tours, 37200 France 2Soft Matter Physics Laboratory, Far Eastern Federal University, Sukhanova 8, Vladivostok, 690950, Russia 3Department of Physics and Astronomy, University of Gent, Krijgslaan 281, S9, B-9000 Gent, Belgium 4School of Natural Sciences, Far Eastern Federal University, Sukhanova 8, Vladivostok, 690950, Russia (Dated: September 8, 2016) We propose a general numerical method to study the Casimir effect in lattice gauge theories. We illustrate the method by calculating the energy density of zero-point fluctuations around two parallel wires of finite static permittivity in Abelian gauge theory in two spatial dimensions. We discuss various subtle issues related to the lattice formulation of the problem and show how they can successfully be resolved. Finally, we calculate the Casimir potential between the wires of a fixed permittivity, extrapolate our results to the limit of ideally conducting wires and demonstrate excellent agreement with a known theoretical result. I. INTRODUCTION lattice discretization) described by spatially-anisotropic and space-dependent static permittivities "(x) and per- meabilities µ(x) at zero and finite temperature in theories The influence of the physical objects on zero-point with various gauge groups. (vacuum) fluctuations is generally known as the Casimir The structure of the paper is as follows. In Sect. II effect [1{3]. The simplest example of the Casimir effect is we review the implementation of the Casimir boundary a modification of the vacuum energy of electromagnetic conditions for ideal conductors and propose its natural field by closely-spaced and perfectly-conducting parallel counterpart in the lattice gauge theory. -
Arxiv:2002.02662V2 [Math.RT]
BLOCKS AND CHARACTERS OF D(2|1; ζ)-MODULES OF NON-INTEGRAL WEIGHTS CHIH-WHI CHEN, SHUN-JEN CHENG, AND LI LUO Abstract. We classify blocks in the BGG category O of modules of non-integral weights for the exceptional Lie superalgebra D(2|1; ζ). We establish various reduction methods, which connect some types of non-integral blocks of D(2|1; ζ) with integral blocks of general linear Lie superalgebras gl(1|1) and gl(2|1). We compute the characters for irreducible D(2|1; ζ)-modules of non-integral weights in O. Contents 1. Introduction 1 2. Preliminaries 3 3. Classification of blocks 10 4. Reduction methods and characters in the generic and 1-integer cases 15 5. Character formulas in 2-integer case 19 6. Primitive spectrum of D(2|1; ζ) 23 References 25 1. Introduction 1.1. Since a Killing-Cartan type classification of finite-dimensional complex simple Lie superalge- bras has been achieved by Kac [Kac77] in 1977 there has been substantial efforts by mathematicians and physicists in the study of their representation theory. The most important class of the simple arXiv:2002.02662v2 [math.RT] 20 Feb 2020 Lie superalgebras is the so-called basic classical, which includes the classical series of types ABCD. Among these basic Lie superalgebras, there are 3 exceptional ones: D(2|1; ζ), G(3) and F (3|1). 1.2. The irreducible character problem is one of the main theme in representation theory of Lie (super)algebras. While complete answers to the irreducible character problem in the BGG cat- egories for basic Lie superalgebras of types ABCD are now known (see [CLW11, CLW15, Ba17, BLW17, BW18]), the BGG category of the exceptional Lie superalgebras were not until recently. -
Duality and Integrability in Topological String Theory
View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by SISSA Digital Library International School of Advanced Studies Mathematical Physics Sector Academic Year 2008–09 PhD Thesis in Mathematical Physics Duality and integrability in topological string theory Candidate Andrea Brini Supervisors External referees Prof. Boris Dubrovin Prof. Marcos Marino˜ Dr. Alessandro Tanzini Dr. Tom Coates 2 Acknowledgements Over the past few years I have benefited from the interaction with many people. I would like to thank first of all my supervisors: Alessandro Tanzini, for introducing me to the subject of this thesis, for his support, and for the fun we had during countless discussions, and Boris Dubrovin, from whose insightful explanations I have learned a lot. It is moreover a privilege to have Marcos Mari˜no and Tom Coates as referees of this thesis, and I would like to thank them for their words and ac- tive support in various occasions. Special thanks are also due to Sara Pasquetti, for her help, suggestions and inexhaustible stress-energy transfer, to Giulio Bonelli for many stimulating and inspiring discussions, and to my collaborators Renzo Cava- lieri, Luca Griguolo and Domenico Seminara. I would finally like to acknowledge the many people I had discussions/correspondence with: Murad Alim, Francesco Benini, Marco Bertola, Vincent Bouchard ;-), Ugo Bruzzo, Mattia Cafasso, Hua-Lian Chang, Michele Cirafici, Tom Claeys, Andrea Collinucci, Emanuel Diaconescu, Bertrand Ey- nard, Jarah Evslin, Fabio Ferrari Ruffino, Barbara -
1 the Superalgebra of the Supersymmetric Quantum Me- Chanics
CBPF-NF-019/07 1 Representations of the 1DN-Extended Supersymmetry Algebra∗ Francesco Toppan CBPF, Rua Dr. Xavier Sigaud 150, 22290-180, Rio de Janeiro (RJ), Brazil. E-mail: [email protected] Abstract I review the present status of the classification of the irreducible representations of the alge- bra of the one-dimensional N− Extended Supersymmetry (the superalgebra of the Supersym- metric Quantum Mechanics) realized by linear derivative operators acting on a finite number of bosonic and fermionic fields. 1 The Superalgebra of the Supersymmetric Quantum Me- chanics The superalgebra of the Supersymmetric Quantum Mechanics (1DN-Extended Supersymme- try Algebra) is given by N odd generators Qi (i =1,...,N) and a single even generator H (the hamiltonian). It is defined by the (anti)-commutation relations {Qi,Qj} =2δijH, [Qi,H]=0. (1) The knowledge of its representation theory is essential for the construction of off-shell invariant actions which can arise as a dimensional reduction of higher dimensional supersymmetric theo- ries and/or can be given by 1D supersymmetric sigma-models associated to some d-dimensional target manifold (see [1] and [2]). Two main classes of (1) representations are considered in the literature: i) the non-linear realizations and ii) the linear representations. Non-linear realizations of (1) are only limited and partially understood (see [3] for recent results and a discussion). Linear representations, on the other hand, have been recently clarified and the program of their classification can be considered largely completed. In this work I will review the main results of the classification of the linear representations and point out which are the open problems. -
Infinitely Generated Clifford Algebras and Wedge Representations of Gl∞|∞ Bradford J
University of Wisconsin Milwaukee UWM Digital Commons Theses and Dissertations May 2015 Infinitely Generated Clifford Algebras and Wedge Representations of gl∞|∞ Bradford J. Schleben University of Wisconsin-Milwaukee Follow this and additional works at: https://dc.uwm.edu/etd Part of the Mathematics Commons Recommended Citation Schleben, Bradford J., "Infinitely Generated Clifford Algebras and Wedge Representations of gl∞|∞" (2015). Theses and Dissertations. 919. https://dc.uwm.edu/etd/919 This Dissertation is brought to you for free and open access by UWM Digital Commons. It has been accepted for inclusion in Theses and Dissertations by an authorized administrator of UWM Digital Commons. For more information, please contact [email protected]. Infinitely Generated Clifford Algebras and Wedge Representations of gl1j1 by Bradford J. Schleben A Dissertation Submitted in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy in Mathematics at The University of Wisconsin{Milwaukee May 2015 ABSTRACT Infinitely Generated Clifford Algebras and Wedge Representations of gl1j1 by Bradford J. Schleben The University of Wisconsin-Milwaukee, 2015 Under the Supervision of Dr. Yi Ming Zou The goal of this dissertation is to explore representations of gl1j1 and associ- ated Clifford superalgebras. The machinery utilized is motivated by developing an alternate superalgebra analogue to the Lie algebra theory developed by Kac [17]. Kac and van de Leur first developed a super analogue, but it had various departures from a natural extension of their Lie algebra approach, made most certainly for the physics consequences. In an effort to establish a natural mathematical analogue, we construct a theory distinct from the super analogue developed by Kac and van de Leur [16]. -
Lectures on Effective Field Theories
Adam Falkowski Lectures on Effective Field Theories Version of September 21, 2020 Abstract Effective field theories (EFTs) are widely used in particle physics and well beyond. The basic idea is to approximate a physical system by integrating out the degrees of freedom that are not relevant in a given experimental setting. These are traded for a set of effective interactions between the remaining degrees of freedom. In these lectures I review the concept, techniques, and applications of the EFT framework. The 1st lecture gives an overview of the EFT landscape. I will review the philosophy, basic techniques, and applications of EFTs. A few prominent examples, such as the Fermi theory, the Euler-Heisenberg Lagrangian, and the SMEFT, are presented to illustrate some salient features of the EFT. In the 2nd lecture I discuss quantitatively the procedure of integrating out heavy particles in a quantum field theory. An explicit example of the tree- and one-loop level matching between an EFT and its UV completion will be discussed in all gory details. The 3rd lecture is devoted to path integral methods of calculating effective Lagrangians. Finally, in the 4th lecture I discuss the EFT approach to constraining new physics beyond the Standard Model (SM). To this end, the so- called SM EFT is introduced, where the SM Lagrangian is extended by a set of non- renormalizable interactions representing the effects of new heavy particles. 1 Contents 1 Illustrated philosophy of EFT3 1.1 Introduction..................................3 1.2 Scaling and power counting.........................6 1.3 Illustration #1: Fermi theory........................8 1.4 Illustration #2: Euler-Heisenberg Lagrangian.............. -
Gauge Theories in Particle Physics
GRADUATE STUDENT SERIES IN PHYSICS Series Editor: Professor Douglas F Brewer, MA, DPhil Emeritus Professor of Experimental Physics, University of Sussex GAUGE THEORIES IN PARTICLE PHYSICS A PRACTICAL INTRODUCTION THIRD EDITION Volume 1 From Relativistic Quantum Mechanics to QED IAN J R AITCHISON Department of Physics University of Oxford ANTHONY J G HEY Department of Electronics and Computer Science University of Southampton CONTENTS Preface to the Third Edition xiii PART 1 INTRODUCTORY SURVEY, ELECTROMAGNETISM AS A GAUGE THEORY, AND RELATIVISTIC QUANTUM MECHANICS 1 Quarks and Leptons 3 1.1 The Standard Model 3 1.2 Levels of structure: from atoms to quarks 5 1.2.1 Atoms ---> nucleus 5 1.2.2 Nuclei -+ nucleons 8 1.2.3 . Nucleons ---> quarks 12 1.3 The generations and flavours of quarks and leptons 18 1.3.1 Lepton flavour 18 1.3.2 Quark flavour 21 2 Partiele Interactions in the Standard Model 28 2.1 Introduction 28 2.2 The Yukawa theory of force as virtual quantum exchange 30 2.3 The one-quantum exchange amplitude 34 2.4 Electromagnetic interactions 35 2.5 Weak interactions 37 2.6 Strong interactions 40 2.7 Gravitational interactions 44 2.8 Summary 48 Problems 49 3 Eleetrornagnetism as a Gauge Theory 53 3.1 Introduction 53 3.2 The Maxwell equations: current conservation 54 3.3 The Maxwell equations: Lorentz covariance and gauge invariance 56 3.4 Gauge invariance (and covariance) in quantum mechanics 60 3.5 The argument reversed: the gauge principle 63 3.6 Comments an the gauge principle in electromagnetism 67 Problems 73 viii CONTENTS 4 -
Lectures on N = 2 Gauge Theory
Preprint typeset in JHEP style - HYPER VERSION Lectures on N = 2 gauge theory Davide Gaiotto Abstract: In a series of four lectures I will review classic results and recent developments in four dimensional N = 2 supersymmetric gauge theory. Lecture 1 and 2 review the standard lore: some basic definitions and the Seiberg-Witten description of the low energy dynamics of various gauge theories. In Lecture 3 we review the six-dimensional engineering approach, which allows one to define a very large class of N = 2 field theories and determine their low energy effective Lagrangian, their S-duality properties and much more. Lecture 4 will focus on properties of extended objects, such as line operators and surface operators. Contents I Lecture 1 1 1. Seiberg-Witten solution of pure SU(2) gauge theory 5 2. Solution of SU(N) gauge theory 7 II Lecture 2 8 3. Nf = 1 SU(2) 10 4. Solution of SU(N) gauge theory with fundamental flavors 11 4.1 Linear quivers of unitary gauge groups 12 Field theories with N = 2 supersymmetry in four dimensions are a beautiful theoretical playground: this amount of supersymmetry allows many exact computations, but does not fix the Lagrangian uniquely. Rather, one can write down a large variety of asymptotically free N = 2 supersymmetric Lagrangians. In this lectures we will not include a review of supersymmetric field theory. We will not give a systematic derivation of the Lagrangian for N = 2 field theories either. We will simply describe whatever facts we need to know at the beginning of each lecture.