Self-interacting neutrinos in the light of cosmological and IceCube observations.

Over the past few decades, the huge influx of data from cosmological and particle physics observations have enabled us to understand and test the viability of the theories. These observations have also yielded some discrepancies which hint towards the new physics. One such discrepancy is the mismatch between the values of the Hubble constant (H0) obtained from the direct local measurements and from the Planck CMB observation within λCDM cosmology. Self-interaction between active neutrinos had been proposed as a solution to the H0 tension. Similar self-interaction can also explain the observed dips in the flux of the neutrinos in IceCube detectors. In this talk, I will explain the H0 tension and observed dips in IceCube as a signature of flavour specific self-interaction between active neutrinos. Self-interaction between sterile neutrinos had also been proposed to make light sterile neutrinos viable with cosmological observations. In this talk, I will also discuss the effect of self interacting light sterile neutrinos on the validity of the inflation models.