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High Energy


QMAP Particles/Cosmology: Kevin Langhoff

Description Speaker: Kevin Langhoff
Title: The Irreducible Axion Background
Room: 3024
Host: Luty
Abstract: Searches for dark matter decaying into photons constrain its lifetime to be many orders of magnitude larger than the age of the Universe. A corollary statement is that the abundance of any particle that can decay into photons over cosmological timescales is constrained to be much smaller than the cold dark-matter density. We show that an irreducible freeze-in contribution to the relic density of axions is in violation of that statement in a large portion of the parameter space. This allows us to set stringent constraints on axions in the mass range 100 eV - 100 MeV. Although I will focus on axions, the argument is more general and can be extended to, for instance, sterile neutrinos.
Date Tue, April 25, 2023
Time 1:30pm-3:00pm PDT
Duration 1 hour 30 minutes
Access Public
Created by High-Energy Seminars
Updated Sat, May 6, 2023 8:00pm PDT
Send Reminder Yes  -  1 day 4 hour 0 minutes before start

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