Title: Dark Matter decay and cosmological Hubble measurement anomaly

Speaker: Prof. Subinoy Das, Indian Institute of Astrophysics, Bengaluru

Abstract: The Hubble tension between the ΛCDM-model-dependent prediction of the current expansion rate H0 using Planck data and direct, model-independent measurements in the local universe from the SH0ES collaboration disagree at >3.5σ. Moreover, there exists a milder ∼2σ tension between similar predictions for the amplitude S8 of matter fluctuations and its measurement in the local universe. As explanations relying on unresolved systematics have not been found, theorists have been exploring explanations for these anomalies that modify the cosmological model, altering early-universe-based predictions for these parameters. However, new cosmological models that attempt to resolve one tension often worsen the other. In this talk, I will investigate a decaying dark matter (DDM) model as a solution to both tensions simultaneously.