Speaker
Dr
Brooks Thomas
(University of Arizona)
Description
In this talk, I will present an alternative framework for dark matter physics in which the dark matter of the universe comprises a vast ensemble of interacting fields with a variety of different masses, mixings, and abundances. The constituents of this ensemble are not required to be stable individually; rather, the decay widths of these fields are balanced against their abundances in such a way that phenomenological viability is ensured. I will begin by discussing the general aspects of the dynamical dark-matter framework and some of its generic cosmological and astrophysical implications. I will then provide a simple, explicit model in which the dark-matter ensemble consists of the KK excitations of an axion-like field propagating in the bulk of a theory with large extra spacetime dimensions. In this model the correct relationship between decay widths and relic abundances arises naturally, and all phenomenological constraints can simultaneously be satisfied.