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VERSION:2.0
CALSCALE:GREGORIAN
PRODID:UW-Madison-Physics-Events
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SEQUENCE:0
UID:UW-Physics-Event-4209
DTSTART:20160906T203000Z
DURATION:PT1H0M0S
DTSTAMP:20260419T075611Z
LAST-MODIFIED:20160825T152017Z
LOCATION:5280 Chamberlin Hall
SUMMARY:The Impact of Self-Interacting Dark Hydrogen on Structure Form
 ation\, Theory Seminar (High Energy/Cosmology)\, Kimberly Boddy\, Univ
 ersity if Hawai I
DESCRIPTION:The standard cosmological model with collisionless\, cold 
 dark matter (CDM) is remarkably successful in describing the observed 
 large-scale structure of the Universe\; however\, on small scales rang
 ing from dwarf spheroidal galaxies to galaxy clusters\, dark matter ha
 los have more cored profiles with lower central densities than those g
 enerated by simulations. An attractive solution to these anomalies is 
 to modify predictions of small-scale structure through dark matter sel
 f-interactions. I will discuss a particular model in which dark matter
  is the analog of hydrogen in a secluded sector. The self-interactions
 \, which include both elastic scatterings as well as inelastic process
 es due to a hyperfine transition\, exhibit the right velocity dependen
 ce to explain the low dark matter density cores seen in spiral galaxie
 s while being consistent with all constraints from observations of clu
 sters of galaxies. Significant cooling losses may occur due to excitat
 ions and subsequent decays of the hyperfine state\, which may affect t
 he evolution of low-mass halos and the early growth of black holes. Fu
 rthermore\, the interaction between dark matter and dark radiation sup
 presses the matter power spectrum at small scales\, resulting in minim
 um halo masses that are significantly larger than those typically pred
 icted by CDM.
URL:https://www.physics.wisc.edu/events/?id=4209
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