A new light on the darkest corner of the landscape

TL;DR

This paper investigates the bounds on scalar potentials from string theory compactifications and presents a numerical example that challenges the Refined de Sitter Swampland conjecture by finding a metastable de Sitter solution.

Contribution

It provides a numerical counterexample to the conjecture within 4D supergravity from massive type IIA string theory compactification.

Findings

Discovered a metastable de Sitter extremum with a single flat direction.

The solution involves spacetime filling sources like O6 planes and KK monopoles.

The example violates the proposed bounds of the conjecture.

Abstract

Motivated by the recently proposed bounds on the slow-roll parameters for scalar potentials arising from string/M-theory compactifications, a.k.a. the Refined de Sitter Swampland conjecture, we explore the sharpness of such constraints within 4D supergravities coming from compactifications of massive type IIA string theory on $\mathbb{T}^{6}/(\mathbb{Z}_{2}\,\times\,\mathbb{Z}_{2})$. With the aid of a numerical technique, known as differential evolution, we are able to find a de Sitter extremum which is fully metastable up to one single flat direction. This solution is supported by spacetime filling sources such as O6 planes and KK monopoles. Our example violates the bound imposed by this conjecture.