D-brane instantons and the effective field theory of flux compactifications

TL;DR

This paper develops an effective field theory framework to describe how fluxes influence D-brane instantons in flux compactifications, unifying non-perturbative effects across various flux backgrounds and including non-geometric fluxes.

Contribution

It introduces a purely 4d effective action approach to incorporate flux effects on D-brane instantons, connecting with topological string theory and special geometry.

Findings

Unified description of non-perturbative effects in flux compactifications

Explicit treatment of fluxes without microscopic models, including non-geometric fluxes

Connections established with topological string theory and special geometry

Abstract

We provide a description of the effects of fluxes on euclidean D-brane instantons purely in terms of the 4d effective action. The effect corresponds to the dressing of the effective non-perturbative 4d effective vertex with 4d flux superpotential interactions, generated when the moduli fields made massive by the flux are integrated out. The description in terms of effective field theory allows a unified description of non-perturbative effects in all flux compactifications of a given underlying fluxless model, globally in the moduli space of the latter. It also allows us to describe explicitly the effects on D-brane instantons of fluxes with no microscopic description, like non-geometric fluxes. At the more formal level, the description has interesting connections with the bulk-boundary map of open-closed two-dimensional topological string theory, and with the $\NN=1$ special geometry.