Out-of-equilibrium production of dark matter in the early universe

par M. Torsten Bringmann (Oslo University)

jeudi 22 sept. 2022, 11:00 → 12:00 Europe/Paris

Petit Amphi (LAPTh)

Dark matter is an essential ingredient of the standard model of cosmology. 

Any theory describing it in terms of hypothetical new particles must therefore 

include a production mechanism that can explain its present abundance, with 

an accuracy matching cosmological observations.  In this talk I will describe 

two generic ways of how dark matter with even very feeble interactions can be 

produced from the primordial thermal bath of standard model particles. The 

first example is commonly known as 'freeze-in' production, where I will report 

on recent updates that facilitate precision calculations of the relic density 

in particular in Higgs portal models. I will then introduce a newly proposed 

alternative production scenario that is characterized by an era of exponential 

('pandemic') growth of the dark matter density in the early universe. As a 

concrete application, I demonstrate how this idea opens up highly relevant 

-- and relatively shortly testable -- new parameter space for sterile neutrino 

dark matter.