When I first decided to write a book on string theory, more than ten years ago, my memories of my student years were much more vivid than they are today. Still, I remember that one of the greatest pleasures was finding a text that made a difficult subject accessible, and I hoped to provide the same for string theory.
Thus, my first purpose was to give a coherent introduction to string theory, based on the Polyakov path integral and conformal field theory.A second purpose was to show how some of the simplest four- dimensional string theories connect with previous ideas for unifying the Standard Model, and to collect general results on the physics of four- dimensional string theories as derived from world-sheet and spacetime symmetries.

Foreword
Preface
Notation
10 Type I and type II superstrings
10.1 The superconformal algebra
10.2 Ramond and Neveu-Schwarz sectors
10.3 Vertex operators and bosonization
10.4 The superconformal ghosts
10.5 Physical states
10.6 Superstring theories in ten dimensions
10.7 Modular invariance
10.8 Divergences of type I theory
Exercises
11 The heterotic string
11.1 World-sheet supersymmetries
11.2 The SO(32) and E8 x E8 heterotic strings
11.3 Other ten-dimensional heterotic strings
11.4 A little Lie algebra
11.5 Current algebras
11.6 The bosonic construction and toroidal compactification
Exercises
12 Superstring interactions
12.1 Low energy supergravity
12.2 Anomalies
12.3 Superspace and superfields
12.4 Tree-level amplitudes
12.5 General amplitudes
12.6 One-loop amplitudes
Exercises
13 D-branes
13.1 T-duality of type II strings
13.2 T-duality of type I strings
13.3 The D-brahe charge and action
13.4 D-brane interactions: statics
13.5 D-brane interactions: dynamics
13.6 D-brane interactions: bound states
Exercises
14 Strings at strong coupling
14.1 Type IIB string and SL(2, Z) duality
14.2 U-duality
14.3 SO(32) type I-heterotic duality
14.4 Type IIA string and M-theory
14.5 The E8 x E8 heterotic string
14.6 What is string theory?
14.7 Is M for matrix?
14.8 Black hole quantum mechanics
Exercises
15 Advanced CFT
15.1 Representations of the Virasoro algebra
15.2 The conformal bootstrap
15.3 Minimal models
15.4 Current algebras
15.5 Coset models
15.6 Representations of the N = 1 superconformal algebra
15.7 Rational CFT
15.8 Renormalization group flows
15.9 Statistical mechanics
Exercises
16 Orbifolds
16.1 Orbifolds of the heterotic string
16.2 Spacetime supersymmetry
16.3 Examples
16.4 Low energy field theory
Exercises
17 Calabi-Yau compactification
17.1 Conditions for N = 1 supersymmetry
17.2 Calabi-Yau manifolds
17.3 Massless spectrum
17.4 Low energy field theory
17.5 Higher corrections
17.6 Generalizations
18 Physics in four dimensions
18.1 Continuous and discrete symmetries
18.2 Gauge symmetries
18.3 Mass scales
18.4 More on unification
18.5 Conditions for spacetime supersymmetry
18.6 Low energy actions
18.7 Supersymmetry breaking in perturbation theory
18.8 Supersymmetry beyond perturbation theory
Exercises
19 Advanced topics
19.1 The N = 2 superconformal algebra
19.2 Type II strings on Calabi-Yau manifolds
19.3 Heterotic string theories with (2,2) SCFT
19.4 N = 2 minimal models
19.5 Gepner models
19.6 Mirror symmetry and applications
19.7 The conifold
19.8 String theories on K3
19.9 String duality below ten dimensions
19.10 Conclusion
Exercises
Appendix B: Spinors and SUSY in various dimensions
B.1 Spinors in various dimensions
B.2 Introduction to supersymmetry: d = 4
B.3 Supersymmetry in d = 2
B.4 Differential forms and generalized gauge fields
B.5 Thirty-two supersymmetries
B.6 Sixteen supersymmetries
B.7 Eight supersymmetries
Exercises
References
Glossary
Index