D-instanton Induced Effective Action and its Gauge Invariance

TL;DR

This paper proves that the effective action induced by D-instantons in string theory maintains gauge invariance for any number of instantons by satisfying the quantum Batalin-Vilkovisky master equation.

Contribution

It generalizes previous proofs to show gauge invariance of the D-instanton induced effective action for arbitrary instanton numbers.

Findings

Effective action respects gauge invariance for any number of D-instantons.

The proof ensures consistency of D-instanton effects with string field theory.

The quantum BV master equation is satisfied in the generalized case.

Abstract

The effect of D-instantons on closed string scattering amplitudes may be encoded into an effective action obtained by integrating out the (transient) open string fields. In order that this respects the gauge invariance of the theory, the sum of the perturbative closed string field theory action and the D-instanton induced effective action must satisfy the quantum Batalin-Vilkovisky master equation. In a previous paper this was proved for the effective action induced by up to two instantons. We generalize the proof for arbitrary number of D-instantons.