Almost classical de Sitter?

TL;DR

This paper investigates whether including 4-derivative string corrections in type II flux compactifications can produce metastable de Sitter vacua, concluding that such corrections do not enable dS solutions in the studied models.

Contribution

It extends the classical de Sitter scenario by incorporating leading string corrections and shows these do not lead to metastable dS vacua in models with O8-planes or D8-branes.

Findings

4-derivative corrections do not produce metastable dS in O8/D8 models

Including corrections does not change the no-go results for dS vacua

Results hold with or without full backreaction considerations

Abstract

The classical-dS scenario in the type II string theories proposes to search for dS vacua of orientifold flux compactifications in a regime where string corrections to the compactified effective field theory are negligible. We study a minimal extension of this scenario in which the leading string corrections to the O-plane/D-brane actions at the 4-derivative order are included but higher orders as well as string corrections in the bulk are self-consistently neglected. Our proposal is motivated by a recent debate about dS solutions with O8-planes which circumvent a classical no-go theorem due to unusual sources leading to so-called permissive boundary conditions for the 10D supergravity fields. We argue that such sources do not arise in classical supergravity but ask whether including the 4-derivative corrections leads to sources that have a similar effect. However, we find that the 4-derivative corrections do not allow meta-stable dS in a class of models with O8-planes and/or D8-branes we consider. We also study related models which in addition contain O6-planes/D6-branes and find that again no meta-stable dS is allowed, both classically and including the 4-derivative corrections. While some of the arguments in this work require the backreaction of the O-plane/D-brane sources to be small, others are valid including the full backreaction.