Constraining de Sitter Space in String Theory

TL;DR

This paper argues that string theory, specifically heterotic and certain type II vacua, cannot produce stable de Sitter space-times, challenging assumptions in string landscape discussions and extending no-go theorems to high curvature regimes.

Contribution

It extends supergravity no-go results to high curvature regimes and clarifies the limitations of string vacua in realizing de Sitter space-times.

Findings

Heterotic string lacks classical de Sitter vacua in four or more dimensions.

Type II vacua without RR fluxes also do not admit de Sitter solutions.

Results suggest caution in using genericity arguments in string landscape theories.

Abstract

We argue that the heterotic string does not have classical vacua corresponding to de Sitter space-times of dimension four or higher. The same conclusion applies to type II vacua in the absence of RR fluxes. Our argument extends prior supergravity no-go results to regimes of high curvature. We discuss the interpretation of the heterotic result from the perspective of dual type II orientifold constructions. Our result suggests that the genericity arguments used in string landscape discussions should be viewed with caution.