de Sitter Swampland Conjecture and the Nature of Dark Energy

Determine whether dark energy is not a constant vacuum energy but instead slowly decays in time, as implied by the de Sitter Swampland conjecture; assess this prediction via cosmological observations.

Background

The Swampland de Sitter conjecture proposes that metastable de Sitter vacua may be absent in consistent quantum gravity, suggesting that cosmic acceleration arises from rolling scalar fields rather than a cosmological constant. The authors present the conjecture’s strongest‑form implication for dark energy and note its potential falsifiability by upcoming observations.

Clarifying the nature of dark energy has significant consequences for both cosmology and the landscape of string theory vacua. If the conjecture holds, it would fundamentally change expectations about late‑time cosmic acceleration and the role of scalar potentials in four‑dimensional EFTs emerging from string theory.