2023-12-15 11:00  P5A-1

Massive Neutrino Self-Interactions and the Hubble Tension

Dr. Shouvik Roy Choudhury

In the Lambda-CDM model, Planck data provides a value of the Hubble constant H0 equal to 67.5 km/s/Mpc, which is around 5-sigma away from the locally measured value from Type Ia Supernovae, H0 equal to 73 km/s/Mpc. This Hubble tension is currently the biggest discrepancy in cosmology. Here we looked at the cosmological model that incorporates massive neutrino non-standard interaction mediated via a heavy scalar, which had previously shown a lot of promise in solving the Hubble tension in the strong interaction regime where the coupling strength is approximately 10^9 times the weak interaction coupling. However, with the latest Planck 2018 data, we found that the Planck high-multipole CMB polarization data disfavours such strong interactions.

Based on: arXiv: 2012.07519 (published in JCAP)