2021/10/18 by Steven J. Clark, Clark, Steven J., Kyriakos Vattis +5
Physics and Astronomy · #Cosmology and Gravitation Theories #Cosmology and Nongalactic Astrophysics (astro-ph.CO) #Dark Matter and Cosmic Phenomena #FOS: Physical sciences #Galaxies: Formation, Evolution, Phenomena #High Energy Physics - Phenomenology (hep-ph)
paper · pdf · doi:10.48550/arxiv.2110.09562
openalex publication_date 2021/10/18 · openalex created_date 2022/07/25 · openalex updated_date 2026/07/28
An only early or only late time alteration to ΛCDM has been inadequate at resolving both the H0 and S8 tensions simultaneously; however, a combination of early and late time alterations to ΛCDM can provide a solution to both tensions. As an illustration, we examine a combined Early Dark Energy - Decaying Dark Matter model. While early dark energy has the ability to resolve the H0 tension, it leads to a discrepancy in S8 measurements. We show that the addition of decaying dark matter helps resolve the S8 discrepancy that would otherwise be enhanced in an early dark energy model, while the latter is able to relieve the H0 disagreement to within the 95th percentile interval. Our results show a preference for the combined model over ΛCDM with Δ\rmAIC = -6.72, hinting that both early and late universe modifications may be necessary to address the cosmological tensions.