Towards de Sitter from 10D

TL;DR

This paper investigates the limitations of achieving de Sitter vacua in type IIB string theory, showing that simple KKLT models cannot be uplifted to de Sitter, but racetrack models can potentially realize such vacua with minimal backreaction.

Contribution

It demonstrates that standard KKLT vacua cannot be uplifted to de Sitter due to backreaction, while proposing racetrack stabilization as a viable alternative for de Sitter uplift.

Findings

KKLT vacua with a single Kahler modulus cannot be uplifted to de Sitter.

Racetrack stabilization can avoid the uplift issue and achieve de Sitter.

De Sitter uplifts are possible with negligible backreaction in racetrack models.

Abstract

Using a 10D lift of non-perturbative volume stabilization in type IIB string theory we study the limitations for obtaining de Sitter vacua. Based on this we find that the simplest KKLT vacua with a single Kahler modulus stabilized by a gaugino condensate cannot be uplifted to de Sitter. Rather, the uplift flattens out due to stronger backreaction on the volume modulus than has previously been anticipated, resulting in vacua which are meta-stable and SUSY breaking, but that are always AdS. However, we also show that setups such as racetrack stabilization can avoid this issue. In these models it is possible to obtain supersymmetric AdS vacua with a cosmological constant that can be tuned to zero while retaining finite moduli stabilization. In this regime, it seems that de Sitter uplifts are possible with negligible backreaction on the internal volume. We exhibit this behavior also from the 10D perspective.