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CALSCALE:GREGORIAN
PRODID:UW-Madison-Physics-Events
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SEQUENCE:0
UID:UW-Physics-Event-3821
DTSTART:20150929T200000Z
DTEND:20150929T210000Z
DTSTAMP:20260419T110500Z
LAST-MODIFIED:20150925T142821Z
LOCATION:5280 Chamberlin Hall
SUMMARY:Cosmological Constraints on the Gravitational Interactions of 
 Matter and Dark Matter\, Theory Seminar (High Energy/Cosmology)\, Ben 
 Stefanek\, University of Wisconsin-Madison
DESCRIPTION:Although there is overwhelming evidence of dark matter fro
 m its gravitational interaction\, we still do not know its precise gra
 vitational interaction strength or whether it obeys the equivalence pr
 inciple. Using the latest available cosmological data and working with
 in the framework of LambdaCDM\, we first update the measurement of the
  Newton's constant for all matter: $G_N=7.26^{+0.27}_{-0.27}times 10^{
 -11} m^3 kg^{-1} s^{-2}$\, which differs by $2.2 sigma$ from the stand
 ard laboratory-based value. In general relativity\, dark matter equiva
 lence principle breaking can be mimicked by a long-range dark matter f
 orce mediated by an ultra light scalar field. Using the Planck three y
 ear data\, we find that the dark matter "fifth-force" strength is cons
 trained to be weaker than $10^{-4}$ of the gravitational force. We als
 o introduce a phenomenological\, post-Newtonian two-fluid description 
 to explicitly break the equivalence principle by introducing a differe
 nce between dark matter inertial and gravitational masses. Depending o
 n the decoupling time of the dark matter and ordinary matter fluids\, 
 the ratio of the dark matter gravitational mass to inertial mass is co
 nstrained to be unity at the $10^{-6}$ level.
URL:https://www.physics.wisc.edu/events/?id=3821
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