The string theory swampland in the Euclid, SKA and Vera Rubin observatory era

TL;DR

This paper explores how upcoming cosmological surveys like SKA, Euclid, and Vera Rubin can test string theory constraints, potentially challenging the de Sitter conjecture through improved bounds on the quintessence potential.

Contribution

It demonstrates that future large-scale astrophysical observations can significantly constrain string theory parameters, providing a nearly model-independent test of the swampland conjectures.

Findings

Combined surveys could tighten bounds on string swampland parameters.

Results challenge the de Sitter conjecture with a bound |V'|/V<0.16.

Future observations may falsify certain string theory models.

Abstract

This article aims at drawing the attention of astronomers on the ability of future cosmological surveys to put constraints on string theory. The fact that "quantum gravity" might be constrained by large scale astrophysical observations is a remarkable fact that has recently concentrated a great amount of interest. In this work, we focus on future observatories and investigate their capability to put string theory, which is sometimes said to be "unfalsifiable", under serious pressure. We show that the combined analysis of SKA, Euclid, and the Vera Rubin observatory - together with Planck results - could improve substantially the current limits on the relevant string swampland parameter. In particular, our analysis leads to a nearly model-independent prospective upper bound on the quintessence potential, |V'|/V<0.16, in strong contradiction with the so-called de Sitter conjecture. Some lines of improvements for the very long run are also drawn, together with generic prospective results, underlining the efficiency of this approach. The conjectures used in this work are discussed pedagogically, together with the cosmological models chosen in the analysis.