Lunch seminar Anish Ghoshal

Abstract:

Light dark sector particles, especially bosons if coupled to the inflaton can be copiously produced during (p)reheating epoch courtesy to Bose enhancement. In many particle physics scenarios such light dark sectors are often invoked to resolve tensions with cosmological bounds from Big Bang Nucleosynthesis (BBN), Cosmic Microwave Background (CMB) and Large Scale Structure (LSS) and dark matter (DM). We will discuss two specific cases - one involving bosonic mediators with light sterile neutrinos invoked in context to several neutrino experimental anomalies and anpther, in context to non-thermal production of dark matter. We will discuss the post-inflationary particle production in a large field inflationary model and highlight the region of the parameter space viable with early universe cosmology. Next we will discuss the spectrum of primordial gravitational (PWG) induced due to inflation in scenarios when after inflation cosmological expansion is non-standard and modified as predicted by various modified gravity theories.