Gravothermalizing into Primordial Black Holes: Here we show how gravothermal catastrophe can aid in the production of primordial black holes within the first second after the birth of universe.
Dark radiation constraints on portal
interactions with hidden sectors
: We show how a null detection of dark radiation in our CMB observations severely limits beyond Standard Model interactions. With future CMB experiments, we show that these limits can be orders of magnitude stronger than what we can probe with terrestrial experiments.
Impact of cannibal domination on the matter power spectrum: In the early universe (within a second after the birth of universe), if the energy density of a novel particle called cannibal determines the expansion rate of the universe, then we show that the dark matter density perturbations are enhanced during that period. This enhancement of dark matter perturbations causes most of dark matter to be bounded in microhalos today, which are potentially observable.
BBN constraints on dark radiation isocurvature: We show that if dark radiation is present during the formation of Helium and Deuterium nuclei in the early universe, then dark radiation density perturbation that is out-of-syn with photon density perturbation causes different amount of Helium and Deuterium to be produced in different patches of the universe.
