Cosmological Constraints on Ensembles of Unstable Particles

by Dr Patrick Stengel (University of Michigan)

Tuesday Dec 6, 2016, 3:00 PM → 4:00 PM Pacific/Honolulu

112 (WAT)

We investigate constraints on models in which multiple particles decay to electromagnetically-interacting final states in the early Universe. In particular, assuming that particles decay only to photons, we derive simple analytic approximations to the constraints which may be applied to ensembles of particles with the most generic set of masses, lifetimes and primordial abundances, based upon the effect of decays on light element abundances, Cosmic Microwave Background distortions, neutral hydrogen ionization, and the diffuse photon flux. We apply these constraints to a motivated example model with a large number of unstable particles decaying in the early Universe.