Double-soft behavior for scalars and gluons from string theory

TL;DR

This paper derives the leading double-soft behavior for gluons and scalars from string theory amplitudes, providing insights into their universal soft limits and connections to gauge field theory.

Contribution

It presents the first detailed calculation of double-soft limits for gluons and scalars within string theory, including non-contiguous cases, linking string results to gauge theory.

Findings

Double-soft behavior for gluons when soft gluons are contiguous and non-contiguous.

Double-soft behavior for scalars from dimensional reduction.

Results applicable to gauge theory in the field theory limit.

Abstract

We compute the leading double-soft behavior for gluons and for the scalars obtained by dimensional reduction of a higher dimensional pure gauge theory, from the scattering amplitudes of gluons and scalars living in the world-volume of a Dp-brane of the bosonic string. In the case of gluons, we compute both the double-soft behavior when the two soft gluons are contiguous as well as when they are not contiguous. From our results, that are valid in string theory, one can easily get the double-soft limit in gauge field theory by sending the string tension to infinity.