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Kim Berghaus
Stony Brook University

Abstract:

If dark energy evolves in time its dynamical component could be dominated by a bath of dark radiation. Since dark energy was subdominant in the early universe, the dark energy radiation evades the usual stringent constraints on extra relativistic species from the cosmic microwave background, allowing for an O(1) fraction of the energy density today to be dark radiation. In this talk, I will discuss how dark energy radiation can emerge from a fundamental theory, its predictions for cosmological observables, as well as discovery potential and constraints with existing and future precision cosmological datasets including measurements of the cosmic microwave background, baryon acoustic oscillations, and supernova data. I’ll conclude with the prospects of measuring the particle content of the dark energy radiation in direct-detection experiments in the presence of interactions between the Standard Model and the dark radiation sector, focusing on neutrinos, axions and dark photons.

bring together experimental and theoretical astroparticle physicists and astronomers. They are held approximately fortnightly, September to November and January to March, and on an ad hoc basis outside of term. They currently take place on Thursdays at 2:30 PM in STI 501 and/or on Zoom. Contact Aaron Vincent if you would like to attend through zoom.