Rutgers University Astrophysics Seminar
Understanding the Impact of Omega_m Constraints on Dark Energy at Either Early or Late Times
Recent uncalibrated supernova measurements from Pantheon+, DES Y5, and Union3 tend to prefer high values of the fractional matter density, Omega_m, relative to CMB + BAO data or even Pantheon supernova constraints. This preference has important consequences on cosmological constraints for both early universe and late universe dark energy models. In this talk, I will highlight some of these consequences. In particular, I examine the effect on sound-horizon-independent data (CMB lensing + supernova + BBN) constraints on early dark energy-like (EDE-like) models, finding that this preference tends to reduce the allowed parameter space where EDE could resolve the Hubble tension. Additionally, I explore how these high Omega_m values contribute to the DESI results showing a preference for dynamical dark energy over a cosmological constant.