On open-closed extension of boundary string field theory

TL;DR

This paper develops a classical open-closed string field theory integrating boundary string field theory for open strings and HIKKO theory for closed strings, ensuring gauge invariance via BV formalism.

Contribution

It introduces a novel open-closed interaction framework using boundary states and clarifies the gauge invariance in both sectors within a BV formalism.

Findings

Open-closed interaction modeled by boundary state overlap.

Closed string sector identified as HIKKO theory.

Gauge invariance established for the combined theory.

Abstract

We investigate a classical open-closed string field theory whose open string sector is given by boundary string field theory. The open-closed interaction is introduced by the overlap of a boundary state with a closed string field. With the help of the Batalin-Vilkovisky formalism, the closed string sector is determined to be the HIKKO closed string field theory. We also discuss the gauge invariance of this theory in both open and closed string sides.