What Is String Theory - J. Polchinski

What Is String Theory - J. Polchinski -...

Info iconThis preview shows pages 1–4. Sign up to view the full content.

View Full Document Right Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: arXiv:hep-th/9411028 v1 3 Nov 1994 NSF-ITP-94-97 hep-th/9411028 WHAT IS STRING THEORY? Joseph Polchinski 1 Institute for Theoretical Physics University of California Santa Barbara, CA 93106-4030 ABSTRACT Lectures presented at the 1994 Les Houches Summer School Fluctuating Geome- tries in Statistical Mechanics and Field Theory. The first part is an introduction to conformal field theory and string perturbation theory. The second part deals with the search for a deeper answer to the question posed in the title. 1 Electronic address: joep@sbitp.itp.ucsb.edu Contents 1 Conformal Field Theory 5 1.1 The Operator Product Expansion . . . . . . . . . . . . . . . . . . . . . . . . 5 1.2 Ward Identities . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 1.3 Conformal Invariance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 1.4 Mode Expansions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 1.5 States and Operators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 1.6 Other CFTs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 1.7 Other Algebras . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 1.8 Riemann Surfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 1.9 CFT on Riemann Surfaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 2 String Theory 44 2.1 Why Strings? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 2.2 String Basics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 2.3 The Spectrum . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 2.4 The Weyl Anomaly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 2.5 BRST Quantization . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 2.6 Generalizations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 2.7 Interactions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68 2.8 Trees and Loops . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74 3 Vacua and Dualities 79 3.1 CFTs and Vacua . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79 3.2 Compactification on a Circle . . . . . . . . . . . . . . . . . . . . . . . . . . . 82 2 3.3 More on R-Duality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 86 3.4 N = 0 in N = 1 in . . . ? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 89 3.5 S-Duality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 92 4 String Field Theory or Not String Field Theory 98 4.1 String Field Theory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99 4.2 Not String Field Theory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103 4.3 High Energy and Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . 109 5 Matrix Models 113 5.1 D = 2 String Theory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .= 2 String Theory ....
View Full Document

Page1 / 154

What Is String Theory - J. Polchinski -...

This preview shows document pages 1 - 4. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online