UNC-CH Physics and Astronomy Masters Defense

Kayla Redmond

“Thermal Production of Dark Matter During an Era of Kination”

Our ignorance of the period between the end of inflation and the beginning of Big Bang Nucleosynthesis limits our understanding of the origins and evolution of dark matter. One possibility is that the Universe’s energy density was dominated by a fast-rolling scalar field while the radiation bath was hot enough to thermally produce dark matter. We investigate the evolution of the dark matter density and derive analytic expressions for the dark matter relic abundance generated during such a period of kination. We use observations of dwarf spheroidal galaxies by the Fermi Gamma-Ray Telescope and observations of the Galactic Center by the High Energy Stereoscopic System to constrain these kination scenarios. If dark matter reaches thermal equilibrium during an era of kination, we are able to place tight constraints on the allowed dark matter mass and the temperature of kination-radiation equality.