The Cosmology of Dark Energy Radiation
Dr. Tanvi Karwal
University of Chicago
Cosmological data finds remarkable consistency with a phenomenological Lambda-CDM model, which sets dark energy to be a cosmological constant, with no dynamics. Within this paradigm, the radiation energy density in the Universe today is < 0.01%. Most departures from ΛCDM that introduce new physics beyond the standard cosmological model in the form of dark radiation find that this additional radiation must be sub-dominant to standard radiation, contributing << 0.01% to the Universe today. But these bounds can be evaded if the dark radiation is not ever-present, but dynamically produced in the late universe via a coupling to dark energy, as postulated by the Dark Energy Radiation scenario. I will present this model and its implications for both the early and late universes, and touch upon prospects for direct detection if we allow interactions with the Standard Model.