D terms from D-branes, gauge invariance and moduli stabilization in flux compactifications

TL;DR

This paper analyzes the structure and origin of D terms in N=1 flux compactifications, exploring their role in gauge invariance, consistency conditions, and moduli stabilization within string theory models.

Contribution

It provides a detailed derivation of D terms from D-brane actions, examines flux and symmetry constraints, and discusses their implications for moduli stabilization in flux compactifications.

Findings

Derived D terms from D-brane actions in flux backgrounds

Established consistency conditions from Bianchi identities and anomalies

Discussed potential of D terms in stabilizing moduli

Abstract

We elucidate the structure of D terms in N=1 orientifold compactifications with fluxes. As a case study, we consider a simple orbifold of the type-IIA theory with D6-branes at angles, O6-planes and general NSNS, RR and Scherk-Schwarz geometrical fluxes. We examine in detail the emergence of D terms, in their standard supergravity form, from an appropriate limit of the D-brane action. We derive the consistency conditions on gauged symmetries and general fluxes coming from brane-localized Bianchi identities, and their relation with the Freed-Witten anomaly. We extend our results to other N=1 compactifications and to non-geometrical fluxes. Finally, we discuss the possible role of U(1) D terms in the stabilization of the untwisted moduli from the closed string sector.