Closed String Field Theory: An Introduction

TL;DR

This paper introduces the fundamental concepts of closed string field theory, discussing background independence, the role of minimal area metrics, and the emergence of Batalin-Vilkovisky structures from conformal field theory state spaces.

Contribution

It provides an accessible overview of core ideas in string field theory, including recent developments and advanced topics.

Findings

Clarifies the concept of a string field and background independence.

Explains how minimal area metrics generate Riemann surfaces with vertices and propagators.

Describes the emergence of Batalin-Vilkovisky structures from conformal field theories.

Abstract

In these introductory notes I explain some basic ideas in string field theory. These include: the concept of a string field, the issue of background independence, the reason why minimal area metrics solve the problem of generating all Riemann surfaces with vertices and propagators, and how Batalin-Vilkovisky structures arise from the state spaces of conformal field theories including ghosts. More advanced topics and recent developments are summarized. (To appear in the proceedings of the 1992 Summer School at Les Houches.)}