The tension between 10D supergravity and dS uplifts

TL;DR

This paper examines the challenges of achieving de Sitter vacua in string theory models, highlighting flattening effects in supergravity that prevent uplift and discussing potential loopholes and swampland implications.

Contribution

It refines previous no-go arguments against dS vacua by analyzing flattening effects in 10D supergravity and explores the Silverstein-Saltman uplift as a simpler setting, suggesting certain AdS vacua are in the Swampland.

Findings

Anti-brane uplifts do not produce dS vacua due to flattening effects.

The Silverstein-Saltman uplift can exhibit flattening effects without UV/IR assumptions.

Parametrically controlled AdS vacua may belong to the Swampland.

Abstract

We elaborate on the recent work of Moritz et. al. where it is argued that anti-brane uplifting in KKLT models never leads to dS vacua. This is due to flattening effects in the effective potential found when treating the gaugino condensate energy momentum in ten-dimensional supergravity. We point out that the Silverstein-Saltman uplift, which effectively dissolves the anti-brane in 3-form fluxes, is a conceptually simpler setting in which flattening effects can be present, without requiring assumptions about UV/IR mixings. Along the way we revise and improve on the arguments of Moritz et. al. and discuss various subleties when studying gaugino condensates from a ten-dimensional point-of-view. In particular, the "no dS" argument is slightly weaker and we emphasize a technical loophole that might allow dS vacua. Finally we suggest that AdS vacua which are parametrically controlled from these flattening effects belong to the Swampland. We comment on the relation with the recent refined dS Swampland inequalities.