The effective action of Double Field Theory
Gerardo Aldazabal, Walter Baron, Diego Marques, Carmen Nunez
TL;DR
This work demonstrates that a generalized Scherk–Schwarz reduction of Double Field Theory on a twisted double torus precisely reproduces the bosonic electric sector of four‑dimensional gauged $\mathcal{N}=4$ supergravity, identifying the 4D gaugings with generalized fluxes $F_{ABC}$ encoded by the internal twist. By extending the internal duality group to $O(D,D+N)$ and exploring rescaling gaugings, the authors show how to realize the full set of electric gaugings within DFT, including additional vectors. The analysis also interprets the internal backgrounds as (non)geometric flux backgrounds connected by T‑duality, and offers Type IIB orientifold and heterotic interpretations that relate the fluxes to conventional string backgrounds and tadpole conditions. The results provide a higher‑dimensional origin for the electric gaugings in $\mathcal{N}=4$ gauged supergravity and highlight the role of the strong constraint and generalized geometry in this correspondence.
Abstract
We perform a generalized Scherk-Schwarz dimensional reduction of Double Field Theory on a twisted double torus. The four dimensional effective action is shown to exactly reproduce the bosonic electric sector of gauged N = 4 supergravity. We present explicit expressions for the gaugings in terms of the twists, and analyze the associated string backgrounds. This framework provides a higher dimensional origin of the gaugings in terms of generalized fluxes.
