Membrane Instantons and de Sitter Vacua

TL;DR

This paper studies membrane instanton effects in type IIA string compactifications, showing their role in moduli stabilization and the existence of meta-stable de Sitter vacua, with solutions matching string theory predictions.

Contribution

It constructs explicit membrane instanton solutions affecting the hypermultiplet geometry and demonstrates their impact on scalar potentials and de Sitter vacua stabilization.

Findings

Membrane instantons are explicitly constructed and match string theory predictions.

Membrane effects influence moduli stabilization in flux compactifications.

Meta-stable de Sitter vacua are shown to exist due to membrane instantons.

Abstract

We investigate membrane instanton effects in type IIA strings compactified on rigid Calabi-Yau manifolds. These effects contribute to the low-energy effective action of the universal hypermultiplet. In the absence of additional fivebrane instantons, the quaternionic geometry of this hypermultiplet is determined by solutions of the three-dimensional Toda equation. We construct solutions describing membrane instantons, and find perfect agreement with the string theory prediction. In the context of flux compactifications we discuss how membrane instantons contribute to the scalar potential and the stabilization of moduli. Finally, we demonstrate the existence of meta-stable de Sitter vacua.