Normalization of the Background Independent Open String Field Theory Action

TL;DR

This paper determines the normalization of the background independent open string field theory action by matching tachyon amplitudes with cubic string field theory, confirming consistency with tachyon condensation conjectures.

Contribution

It provides a precise normalization of the open string field theory action by comparing on-shell tachyon amplitudes, ensuring consistency with tachyon condensation properties.

Findings

Normalization factor matches cubic string field theory results

Confirms conjectured properties of the tachyon potential

Ensures consistency with tachyon condensation theories

Abstract

It has been shown recently that the background independent open string field theory provides an exact description of the tachyon condensation on unstable D-branes of bosonic string theory. In this analysis the overall normalisation of the action was chosen so that it reproduces the conjectured relations involving tachyon condensation. In this paper we fix this normalisation by comparing the on-shell three tachyon amplitude computed from the background independent open string field theory with the same amplitude computed from the cubic open string field theory, which in turn agrees with the result of the first quantised theory. We find that this normalisation factor is in precise agreement with the one required for verifying the conjectured properties of the tachyon potential.