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SUMMARY:Can Dark Matter be a Bose-Einstein Condensate?
DTSTART;VALUE=DATE-TIME:20150521T073000Z
DTEND;VALUE=DATE-TIME:20150521T074500Z
DTSTAMP;VALUE=DATE-TIME:20191023T052444Z
UID:indico-contribution-787701@indico.cern.ch
DESCRIPTION:Speakers: Tiberiu Harko (Department of Mathematics\, Universit
y College London\, Gower Street\, London WC1E 6BT\, United Kingdom)\nWe co
nsider the possibility that the dark matter\, which is required to explain
the dynamics of the neutral hydrogen clouds at large distances from the g
alactic center\, could be in the form of a Bose-Einstein condensate. To st
udy the condensate we use the non-relativistic Gross-Pitaevskii equation.
By introducing the Madelung representation of the wave function\, we formu
late the dynamics of the system in terms of the continuity equation and of
the hydrodynamic Euler equations. Hence dark matter can be described as a
non-relativistic\, Newtonian Bose-Einstein gravitational condensate gas\,
whose density and pressure are related by a barotropic equation of state.
In the case of a condensate with quartic non-linearity\, the equation of
state is polytropic with index n=1. To test the validity of the model we f
it the Newtonian tangential velocity equation of the model with a sample o
f rotation curves of low surface brightness and dwarf galaxies\, respectiv
ely. We find a very good agreement between the theoretical rotation curves
and the observational data for the low surface brightness galaxies. The d
eflection of photons passing through the dark matter halos is also analyze
d\, and the bending angle of light is computed. The bending angle obtained
for the Bose-Einstein condensate is larger than that predicted by standar
d general relativistic and dark matter models. Therefore the study of the
light deflection by galaxies and the gravitational lensing could discrimin
ate between the Bose-Einstein condensate dark matter model and other dark
matter models.\n\nhttps://indico.cern.ch/event/336199/contributions/787701
/
LOCATION: White Lotus
URL:https://indico.cern.ch/event/336199/contributions/787701/
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