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SUMMARY:Neutrinos and Other Dark Lights:  Cosmological Constraints - Lloyd
  Knox (UC Davis)
DTSTART:20120425T124500Z
DTEND:20120425T131500Z
UID:TALK37643@talks.cam.ac.uk
CONTACT:Ben Davies
DESCRIPTION:A number of lines of evidence\, both laboratory and astrophysi
 cal\,  \nsuggest that there are extra (sterile) neutrino species\, or othe
 rwise  \nextra light and dark degrees of freedom ('dark lights') than exis
 t in  \nthe standard model of particle physics.  I will review the physica
 l  \norigin of cosmological constraints on $N_{\\rm eff}$ which is the  \n
 energy density in dark lights expressed in units of the contribution  \nfr
 om one active and massless neutrino species.  I will also review the  \ncu
 rrent constraints from light element abundances\, high-resolution  \ncosmi
 c microwave background data\, distance vs. redshift measurements\,  \nand 
 galaxy cluster abundances.\n\n
LOCATION:Sackler Lecture Theatre\, IoA
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