Gauged Supergravity from Dimensional Reduction

TL;DR

This paper derives a massive N=4 supergravity theory in four dimensions from heterotic string compactification using a generalized Scherk-Schwarz reduction, revealing a new gauging of a Heisenberg subgroup within the global symmetry group.

Contribution

It demonstrates how to obtain a specific massive supergravity via a generalized reduction and identifies the gauging of a Heisenberg group as the key mechanism.

Findings

Explicit derivation of the massive N=4 supergravity from heterotic string compactification.

Identification of the Heisenberg group as a gauge symmetry in the reduced theory.

Connection between Scherk-Schwarz reduction and gauged supergravity frameworks.

Abstract

We perform a generalised Scherk-Schwarz reduction of the effective action of the heterotic string on T^6 to obtain a massive N=4 supergravity theory in four dimensions. The local symmetry-group of the resulting d=4 theory includes a Heisenberg group, which is a subgroup of the global O(6,6+n) obtained in the standard reduction. We show explicitly that the same theory can be obtained by gauging this Heisenberg group in d=4, N=4 supergravity.