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VERSION:2.0
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PRODID:UW-Madison-Physics-Events
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SEQUENCE:2
UID:UW-Physics-Event-5214
DTSTART:20191211T220000Z
DTEND:20191211T230000Z
DTSTAMP:20260415T233051Z
LAST-MODIFIED:20191219T193340Z
LOCATION:5280 Chamberlin Hall
SUMMARY:Dark Matter and Dark Radiation from Primordial Black Hole Domi
 nation\, Theory Seminar (High Energy/Cosmology)\, Gordan Krnjaic\, Fer
 milab
DESCRIPTION:If even a relatively small number of black holes were crea
 ted in the early universe\, they will constitute an increasingly large
  fraction of the total energy density as space expands. It is thus wel
 l-motivated to consider scenarios in which the early universe included
  an era in which primordial black holes dominated the total energy den
 sity. Within this context\, we consider Hawking radiation as a mechani
 sm to produce both dark radiation and dark matter. If the early univer
 se included a black hole dominated era\, we find that Hawking radiatio
 n will produce dark radiation at a level ΔNeff∼0.03−0.2 for each 
 light and decoupled species of spin 0\, 1/2\, or 1. This range is well
  suited to relax the tension between late and early-time Hubble determ
 inations\, and is within the reach of upcoming CMB experiments. The da
 rk matter could also originate as Hawking radiation in a black hole do
 minated early universe\, although such dark matter candidates must be 
 very heavy (mDM>1011 GeV) if they are to avoid exceeding the measured 
 abundance.
URL:https://www.physics.wisc.edu/events/?id=5214
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