Higher-derivative Heterotic Double Field Theory and Classical Double Copy

TL;DR

This paper extends heterotic Double Field Theory with higher-derivative terms, employing the generalized Kerr-Schild ansatz to construct solutions and exploring the classical double copy structure with higher-derivative corrections.

Contribution

It introduces a higher-derivative heterotic DFT framework using GKSA and analyzes the classical double copy with higher-derivative effects.

Findings

Reproduces higher-derivative heterotic background solutions.

Establishes a connection between null vectors and $U(1)$ gauge fields.

Derives Maxwell equations with higher-derivative corrections.

Abstract

The generalized Kerr-Schild ansatz (GKSA) is a powerful tool for constructing exact solutions in Double Field Theory (DFT). In this paper we focus in the heterotic formulation of DFT, considering up to four-derivative terms in the action principle, while the field content is perturbed by the GKSA. We study the inclusion of the generalized version of the Green-Schwarz mechanism to this setup, in order to reproduce the low energy effective heterotic supergravity upon parametrization. This formalism reproduces higher-derivative heterotic background solutions where the metric tensor and Kalb-Ramond field are perturbed by a pair of null vectors. Next we study higher-derivative contributions to the classical double copy structure. After a suitable identification of the null vectors with a pair of $U(1)$ gauge fields, the dynamics is given by a pair of Maxwell equations plus higher derivative corrections in agreement with the KLT relation.