High-Energy Physics & RIKEN Theory Seminar

"Relaxing the Cosmological Constant and Dark Energy Radiation"

Presented by David Kaplan, Johns Hopkins University

Thursday, April 22, 2021, 11:00 am — Videoconference / Virtual Event (see link below)

Abstract: The smallness of the cosmological constant has yet to be understood in our current theories of nature.


I will argue that a dynamical (and non-antropic) explanation suggests that today's dark energy has a dynamical component.


I will show that if dark energy evolves in time, its dynamical component could be dominated by a bath of dark radiation.


Within current constraints this radiation could have up to ∼103 times more energy density than the cosmic microwave background.


I will show models that produce different forms of dark radiation such as hidden photons, milli-charged particles and even Standard Model neutrinos.


I will also show that the late-time cosmology is potentially distinguishable from a cosmological constant or normal quintessence. If the radiation couples to the standard model, it may be directly testable in laboratory experiments!

Hosted by: Julia Gehrlein

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