Heterotic Black Holes in Duality-Invariant Formalism

TL;DR

This paper explores heterotic string effective theory in two dimensions using a duality-invariant formalism, analyzing charged black hole solutions and their dual geometries with a focus on singularities and higher derivative corrections.

Contribution

It introduces a duality-invariant formalism for heterotic strings, extends known solutions to multiple abelian fields, and discusses the properties of charged black holes within this framework.

Findings

Analysis of dual geometries with O(1,2; R) symmetry.

Extension of non-perturbative solutions to multiple abelian fields.

Insights into singularities and gauge dependence in heterotic black holes.

Abstract

We consider the effective theory of heterotic strings in two spacetime dimensions, in a double field theory-inspired formalism, manifestly consistent with $T$-duality in string theory. Restricting the gauge group to a single $\mathrm{U}(1)$, we study the charged black hole solution and perform a precise analysis of the properties of the dual geometry with the $\mathrm{O}(1,2; \mathbb{R})$-valued generalized metric. We comment on some aspects related to singularities and gauge dependence. We show that the classification program for higher derivative corrections can also be applied to the heterotic case. We further elucidate how a previously proposed solution to the equations of motion, parametrized in a manner fully non-perturbative in $\alpha'$, can be extended to the scenario with $r$ abelian fields and the corresponding $\mathrm{O}(1,1+r; \mathbb{R})$ symmetry. We discuss some novel features of the solution for charged black holes.