Quintessential Implications of the presence of AdS in the Dark Energy sector
Purba Mukherjee, Dharmendra Kumar, Anjan A Sen
公開日: 2025/1/30
Abstract
We report evidence for an Anti-de Sitter (AdS) vacuum, equivalently, a negative cosmological constant (nCC) in the dark energy (DE) sector at more than $2\sigma$ significance. Our joint analysis uses DESI BAO, DESY5 supernovae, and P-ACT CMB (ACT-DR6 + Planck) measurements. We also use the KiDS weak lensing measurement to cross-check $S_{8}$ consistency. Within the Chevallier-Polarski-Linder parametrization for evolving part of the DE, the inclusion of an AdS term eliminates the need for phantom behaviour, opening a theoretically natural, non-phantom parameter space. A negative cosmological constant also implies a finite cosmic lifetime, linking observational DE phenomenology to deep questions in quantum gravity and string theory.