Table of Contents
Author biography xiii
1 Introduction 1-1
References 1-4
Part I String theory
2 String theory 2-1
2.1 Actions, symmetries and solutions 2-1
2.1.1 Polyakov action 2-1
2.1.2 Boundary conditions and symmetries 2-3
2.1.3 Closed string solutions 2-5
2.1.4 Open string solutions 2-9
2.2 Canonical quantization and Virasoro algebra 2-10
2.2.1 Canonical quantization 2-10
2.2.2 Virasoro algebra 2-13
2.3 Spurious states and critical strings 2-17
2.3.1 Spurious states 2-17
2.3.2 Critical strings 2-19
2.4 Lightcone gauge quantization 2-20
2.4.1 Critical strings 2-20
2.4.2 Rigorous proof 2-23
2.4.3 Spectrum 2-23
2.5 Exercises 2-24
References 2-42
3 Polyakov path integral 3-1
3.1 Gauge fixing and Fadeev-Popov ghosts 3-1
3.2 The energy-momentum tensor 3-4
3.3 Quantization of the ghosts 3-7
3.3.1 The open string 3-7
3.3.2 The closed string 3-8
3.3.3 Virasoro generators 3-9
3.4 BRST symmetry 3-12
3.4.1 Gauge theory 3-12
3.4.2 General case 3-13
3.4.3 String theory 3-15
3.5 Exercises 3-22
References 3-22
4 Introduction to conformal field theory 4-1
4.1 The conformal groups SO(p + 1, q + 1) 4-1
4.2 The conformal group in two dimensions 4-3
4.3 The energy-momentum tensor 4-6
4.4 The operator product expansion 4-8
4.5 Conformal field theory and BRST quantization 4-18
4.6 Representation theory of the Virasoro algebra 4-27
4.6.1 Virasoro algebra revisited 4-27
4.6.2 Overview of representation theory 4-28
4.7 Theorem 4-31
4.8 Exercises 4-32
References 4-35
5 Superstring theory essentials 5-1
5.1 The superparticle 5-1
5.1.1 Bosonic particle 5-1
5.1.2 The superparticle 5-2
5.1.3 Action 5-3
5.1.4 The k-symmetry 5-5
5.2 The Green-Schwarz superstring 5-6
5.3 The Ramond-Neveu-Schwarz super string 5-9
5.3.1 Supersymmetric action on the worldsheet 5-9
5.3.2 Energy-momentum tensor and supercurrent 5-10
5.3.3 Super-Virasoro constraints 5-14
5.3.4 Boundary conditions (Ramond and Neveu-Schwarz) 5-16
5.4 Canonical quantization 5-18
5.4.1 Commutation relations 5-18
5.4.2 Ramond (fermionic) and Neveu-Schwarz (bosonic) open string sectors 5-20
5.4.3 Super-Virasoro algebra 5-23
5.5 The light cone/path integral quantization 5-25
5.5.1 The light cone quantization and critical dimension 5-25
5.5.2 The GSO conditions and superstring spectrum 5-26
5.6 Other very important topics 5-31
5.7 Exercises 5-31
References 5-34
Part II Matrix string theory
6 A lightning introduction to superstring theory and some related topics 6-1
6.1 Quantum black holes 6-1
6.1.1 Schwarzschild black hole 6-2
6.1.2 Hawking temperature 6-2
6.1.3 Page curve and unitarity 6-5
6.1.4 Information loss problem 6-5
6.1.5 Thermodynamics 6-7
6.2 Some string theory and conformal field theory 6-7
6.2.1 The conformal anomaly 6-7
6.2.2 The operator product expansion 6-9
6.2.3 The be CFT 6-12
6.2.4 The superconformal field theory 6-14
6.2.5 Vertex operators 6-14
6.2.6 Background fields 6-15
6.2.7 Beta function: finiteness and Weyl invariance 6-17
6.2.8 String perturbation expansions 6-19
6.2.9 Spectrum of type II string theory 6-20
6.3 On Dp-branes and T-duality 6-23
6.3.1 Introductory remarks 6-23
6.3.2 Coupling to abelian gauge fields 6-24
6.3.3 Symmetry under the exchange of momentum and winding 6-25
6.3.4 Symmetry under the exchange of Neumann and Dirichlet 6-27
6.3.5 Chan-Paton factors 6-28
6.3.6 Electromagnetism on a circle and Wislon lines 6-29
6.3.7 The D-branes on the dual circle 6-31
6.4 Quantum gravity in two dimensions 6-33
6.4.1 Dynamical triangulation 6-34
6.4.2 Matrix models of D = 0 string theory 6-35
6.4.3 Matrix models of D = 1 string theory 6-37
6.4.4 Preliminary synthesis 6-38
6.5 Exercise 6-39
References 6-39
7 M-(atrix) theory and matrix string theory 7-1
7.1 The quantized membrane 7-1
7.2 The IKKT model or type IIB matrix model 7-6
7.3 The BFSS model from dimensional reduction 7-9
7.4 Introducing gauge/gravity duality 7-12
7.4.1 Dimensional reduction to p + 1 dimensions 7-12
7.4.2 Dp-branes revisited 7-13
7.4.3 The corresponding gravity dual 7-16
7.5 Black hole unitarity from M-theory 7-19
7.5.1 The black 0-brane 7-19
7.5.2 Supergravity in 11 dimensions and M-wave solution 7-20
7.5.3 Type IIA string theory at strong couplings is M-Theory 7-26
7.6 M-theory prediction for quantum black holes 7-28
7.6.1 Quantum gravity corrections 7-28
7.6.2 Non-perturbative tests of the gauge/gravity duality 7-31
7.7 Matrix string theory 7-34
7.8 The black hole and confinement phase transitions 7-37
7.8.1 The black-hole/black-string phase transition 7-37
7.8.2 The confinement/deconfinement phase transition 7-39
7.8.3 The mass gap and the Gaussian structure 7-44
7.8.4 The large d approximation 7-46
7.8.5 High temperature limit 7-48
7.9 The discrete light-cone quantization (DLCQ) and infinite momentum frame (IMF) 7-49
7.9.1 Light-cone quantization and discrete light-cone quantization 7-49
7.9.2 Infinite momentum frame and BFSS conjecture 7-52
7.9.3 More on light-like versus spacelike compactifications 7-53
7.10 M-(atrix) theory in pp-wave spacetimes 7-56
7.10.1 The pp-wave spacetimes and Penrose limit 7-56
7.10.2 The BMN matrix model 7-61
7.10.3 Construction of the BMN matrix model 7-61
7.10.4 Compactification on R × S3 7-68
7.10.5 Dimensional reduction 7-75
7.11 Other matrix models 7-83
7.12 Exercises 7-84
References 7-84
8 Type IIB matrix model 8-1
8.1 The IKKT model in the Gaussian expansion method 8-1
8.2 Yang-Mills matrix cosmology 8-4
8.2.1 Lorentzian type IIB matrix model 8-4
8.2.2 Spontaneous symmetry breaking and continuum and infinite volume limits 8-8
8.2.3 Expansion 8-10
8.2.4 Role of noncommutativity 8-12
8.2.5 Other related work 8-17
8.3 Emergent gravity: introductory remarks 8-17
8.3.1 Noncommutative electromagnetism is a gravity theory 8-17
8.3.2 Seiberg-Witten map 8-21
8.4 Fuzzy spheres and fuzzy CPn 8-24
8.4.1 Co-adjoint orbits 8-25
8.4.2 Fuzzy projective space CP2 8-27
8.4.3 Tangent projective module on fuzzy CP2 8-28
8.4.4 Yang-Mills matrix models for fuzzy CPk 8-30
8.4.5 Coherent states 8-31
8.4.6 Star product 8-34
8.4.7 Fuzzy derivatives 8-37
8.5 Fuzzy S4N: symplectic and Poisson structures 8-38
8.5.1 The spectral triple and fuzzy CPkN: another look 8-38
8.5.2 Fuzzy S4N 8-42
8.5.3 Hopf map 8-48
8.5.4 Poisson structure 8-49
8.5.5 Coherent state 8-50
8.5.6 Focal flatness 8-51
8.5.7 Noncommutativity scale 8-52
8.5.8 Matrix model 8-53
8.6 Emergent matrix gravity 8-57
8.6.1 Fluctuations on fuzzy S4N 8-57
8.6.2 Gauge transformations 8-59
8.6.3 Emergent geometry 8-62
8.6.4 Emergent gauge theory 8-65
8.6.5 Emergent gravity: Einstein equations 8-68
8.7 Emergent quantum gravity from multitrace matrix models 8-73
8.8 Exercise 8-73
References 8-74
Appendix A Algorithms and Monte Carlo codes for the matrix models of string theory A-1