Seminarium "Teoria cząstek elementarnych i kosmologia"

According to the standard model of cosmology, the Universe at its very beginning underwent a phase of a rapid, exponential expansion, followed by a reheating period. During this epoch, the energy density, initially accumulated in oscillations of the inflaton field, was injected into the visible sector, eventually setting the initial conditions for the hot big bang. In this talk, I will discuss the production of the Standard Model (SM) radiation and dark matter adopting a generic post-inflationary scenario with a non-standard expansion history. In particular, I will explore the Higgs boson-induced reheating, assuming that it is achieved through a universal inflaton-Higgs coupling $\phi |\mathcal{H}|^2$. In presence of such interaction, the Higgs doublet acquires a $\phi$-dependent mass which generates a vacuum expectation value due to the inflaton oscillations and breaks the SM gauge symmetry. The non-zero mass of the Higgs field leads to a time-dependent inflaton decay rate during the reheating period in both standard and modified cosmologies. This, in turn, has non-trivial consequences for the dynamics of the reheating period, affecting the evolution of the radiation energy density and thus the UV freeze-in dark matter production.

slides: https://mycloud.fuw.edu.pl/index.php/s/RsX9Lozq6ZCTstR