Multiloop Amplitudes of Light-cone Gauge Bosonic String Field Theory in Noncritical Dimensions

TL;DR

This paper reformulates multiloop amplitudes of light-cone gauge bosonic string theory in noncritical dimensions into a BRST invariant form, advancing understanding of dimensional regularization in string field theory.

Contribution

It introduces a nonstandard worldsheet theory to achieve BRST invariance for multiloop amplitudes in noncritical dimensions.

Findings

Amplitudes are recast into BRST invariant form.

Provides a foundation for testing dimensional regularization in superstring theory.

First step towards multiloop analysis in noncritical string dimensions.

Abstract

We study the multiloop amplitudes of the light-cone gauge closed bosonic string field theory for $d \neq 26$. We show that the amplitudes can be recast into a BRST invariant form by adding a nonstandard worldsheet theory for the longitudinal variables $X^{\pm}$ and the reparametrization ghost system. The results obtained in this paper for bosonic strings provide a first step towards the examination whether the dimensional regularization works for the multiloop amplitudes of the light-cone gauge superstring field theory.