Higher-derivative heterotic Double Field Theory and classical double copy

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.

Automated summary

The generalized Kerr-Schild ansatz (GKSA) is utilized to construct exact solutions in Double Field Theory (DFT), particularly focusing on the heterotic formulation and including up to four-derivative terms. The generalized version of the Green-Schwarz mechanism is incorporated to reproduce low energy effective heterotic supergravity, with perturbations in the metric tensor and Kalb-Ramond field by a pair of null vectors. Higher-derivative contributions to the classical double copy structure are also studied, showing agreement with the KLT relation after suitable identification of the null vectors with a pair of U(1) gauge fields.