Double Field Theory description of Heterotic gauge symmetry enhancing-breaking

TL;DR

This paper develops a Double Field Theory framework to describe gauge symmetry enhancement and breaking in heterotic strings, linking fluxes to structure constants and moduli-dependent phenomena.

Contribution

It extends DFT to heterotic strings by incorporating gauge symmetry enhancement and breaking, including fermions, based on tangent frame extensions and generalized compactifications.

Findings

Fluxes correspond to structure constants at self-dual points.

Symmetry breaking is achieved through moduli displacements.

Gauge bosons acquire masses proportional to fluxes.

Abstract

A Double Field Theory (DFT) description of gauge symmetry enhancing-breaking in the heterotic string is presented. The construction, based on previous results for the bosonic string, relies on the extension of the tangent frame of DFT. The fluxes of a Scherk-Schwarz like generalized toroidal compactification are moduli dependent and become identified with the structure constants of the enhanced group at fixed "self-dual" points in moduli space. Slight displacements from such points provide the breaking of the symmetry, gauge bosons acquiring masses proportional to fluxes. The inclusion of fermions is also discussed.