How Light Can Dark Matter Particles Be?
Speaker
Date
Time
Place
Cosmology Hall (Room 7W3)
Abstract
I will argue that if dark matter is produced via processes with subhorizon correlation length in the early universe, then there is a lower bound on the mass of dark matter particles [m > 10^(-19) eV]. For such dark matter, there is both (i) a free streaming suppression and (ii) white-noise enhancement in the dark matter density power spectrum. The absence of these in the existing observational data (for example, Ly-a) provides a bound on the mass. Beyond the bound, I will present a calculation framework for understanding the growth of structure where warmth and/or white noise are relevant. I will discuss nonlinear phenomenon (eg. solitons), resulting from the large initially isocurvature perturbations on small scales. Time permitting, I will include provide examples of growth of structure in multicomponent wave and particle dark matter.
Biography
Mustafa Amin is a theoretical cosmologist and Professor of Physics and Astronomy at Rice University. He earned his Ph.D. from Stanford University and has held research positions at MIT and Cambridge. His research focuses on the physics of the early universe, particularly the dynamics of cosmic inflation, preheating, and the nonlinear processes that shape the universe's evolution shortly after the Big Bang.