Gravitational Couplings on D-brane Revisited

TL;DR

This paper revisits the effective gravitational couplings on D-branes, incorporating field redefinitions to refine the action up to order '^2, based on string scattering amplitudes and ghost-free conditions.

Contribution

It provides a revised derivation of gravitational couplings on D-branes including field redefinitions, extending the effective action to '^2 order.

Findings

Effective action includes field redefinitions.

Gravitational couplings are fixed up to '^2 order.

Revised couplings align with string scattering data.

Abstract

Gravitational couplings in bulk space-time include those terms which are fixed by scattering amplitude of strings and ambiguous terms that are coming from the field redefinitions. These field redefinitions can be fixed in the bulk by ghost-free condition. In this paper we have revised the effective gravitational couplings on D-branes by including the field redefinitions. We find the gravitational effective action up to $\alpha'^2$-order.