Supersymmetric non-abelian Born-Infeld revisited

TL;DR

This paper derives the non-abelian Born-Infeld action with fermions from string theory amplitudes at order alpha'^2, showing it can be expressed as a symmetrised trace after field redefinitions, and discusses limitations of non-abelian kappa-symmetry.

Contribution

It provides a derivation of the non-abelian Born-Infeld action including fermions from string amplitudes and analyzes the applicability of non-abelian kappa-symmetry.

Findings

All terms at order alpha'^2 can be written as a symmetrised trace after field redefinition.

The non-abelian kappa-symmetry cannot be extended to cubic orders in the Born-Infeld curvature.

The derived action aligns with string scattering amplitude results.

Abstract

We determine the non-abelian Born-Infeld action, including fermions, as it results from the four-point tree-level open superstring scattering amplitudes at order alpha'^2. We find that, after an appropriate field redefinition all terms at this order can be written as a symmetrised trace. We confront this action with the results that follow from kappa-symmetry and conclude that the recently proposed non-abelian kappa-symmetry cannot be extended to cubic orders in the Born-Infeld curvature.