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Article: Can dark matter be a Bose-Einstein condensate?

TitleCan dark matter be a Bose-Einstein condensate?
Authors
KeywordsDark Matter
Dark Matter Simulations
Issue Date2007
PublisherInstitute of Physics Publishing. The Journal's web site is located at http://www.iop.org/EJ/journal/JCAP
Citation
Journal of Cosmology and Astroparticle Physics, 2007 n. 6 How to Cite?
AbstractWe consider the possibility that the dark matter which is required to explain the dynamics of the neutral hydrogen clouds at large distances from the galactic centre could be in the form of a Bose-Einstein condensate. To study the condensate we use the non-relativistic Gross-Pitaevskii equation. By introducing the Madelung representation of the wavefunction, we formulate 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. In the framework of the Thomas-Fermi approximation the structure of the Newtonian gravitational condensate is described by the Lane-Emden equation, which can be exactly solved. General relativistic configurations with quartic non-linearity are studied, by numerically integrating the structure equations. The basic parameters (mass and radius) of the Bose-Einstein condensate dark matter halos sensitively depend on the mass of the condensed particle and of the scattering length. To test the validity of the model we fit the Newtonian tangential velocity equation of the model with a sample of rotation curves of low surface brightness and dwarf galaxies, respectively. We find a very good agreement between the theoretical rotation curves and the observational data for the low surface brightness galaxies. The deflection of photons passing through the dark matter halos is also analysed, and the bending angle of light is computed. The bending angle obtained for the Bose-Einstein condensate is larger than that predicted by standard general relativistic and dark matter models. The angular radii of the Einstein rings are obtained in the small angle approximation. Therefore the study of the light deflection by galaxies and the gravitational lensing could discriminate between the Bose-Einstein condensate dark matter model and other dark matter models. © IOP Publishing Ltd.
Persistent Identifierhttp://hdl.handle.net/10722/91826
ISSN
2015 Impact Factor: 5.634
2015 SCImago Journal Rankings: 0.652
ISI Accession Number ID
References

 

DC FieldValueLanguage
dc.contributor.authorBöhmer, CGen_HK
dc.contributor.authorHarko, Ten_HK
dc.date.accessioned2010-09-17T10:27:45Z-
dc.date.available2010-09-17T10:27:45Z-
dc.date.issued2007en_HK
dc.identifier.citationJournal of Cosmology and Astroparticle Physics, 2007 n. 6en_HK
dc.identifier.issn1475-7516en_HK
dc.identifier.urihttp://hdl.handle.net/10722/91826-
dc.description.abstractWe consider the possibility that the dark matter which is required to explain the dynamics of the neutral hydrogen clouds at large distances from the galactic centre could be in the form of a Bose-Einstein condensate. To study the condensate we use the non-relativistic Gross-Pitaevskii equation. By introducing the Madelung representation of the wavefunction, we formulate 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. In the framework of the Thomas-Fermi approximation the structure of the Newtonian gravitational condensate is described by the Lane-Emden equation, which can be exactly solved. General relativistic configurations with quartic non-linearity are studied, by numerically integrating the structure equations. The basic parameters (mass and radius) of the Bose-Einstein condensate dark matter halos sensitively depend on the mass of the condensed particle and of the scattering length. To test the validity of the model we fit the Newtonian tangential velocity equation of the model with a sample of rotation curves of low surface brightness and dwarf galaxies, respectively. We find a very good agreement between the theoretical rotation curves and the observational data for the low surface brightness galaxies. The deflection of photons passing through the dark matter halos is also analysed, and the bending angle of light is computed. The bending angle obtained for the Bose-Einstein condensate is larger than that predicted by standard general relativistic and dark matter models. The angular radii of the Einstein rings are obtained in the small angle approximation. Therefore the study of the light deflection by galaxies and the gravitational lensing could discriminate between the Bose-Einstein condensate dark matter model and other dark matter models. © IOP Publishing Ltd.en_HK
dc.languageengen_HK
dc.publisherInstitute of Physics Publishing. The Journal's web site is located at http://www.iop.org/EJ/journal/JCAPen_HK
dc.relation.ispartofJournal of Cosmology and Astroparticle Physicsen_HK
dc.subjectDark Matteren_HK
dc.subjectDark Matter Simulationsen_HK
dc.titleCan dark matter be a Bose-Einstein condensate?en_HK
dc.typeArticleen_HK
dc.identifier.emailHarko, TC:harko@hkucc.hku.hken_HK
dc.identifier.authorityHarko, TC=rp1333en_HK
dc.description.naturelink_to_subscribed_fulltext-
dc.identifier.doi10.1088/1475-7516/2007/06/025en_HK
dc.identifier.scopuseid_2-s2.0-34548623343en_HK
dc.relation.referenceshttp://www.scopus.com/mlt/select.url?eid=2-s2.0-34548623343&selection=ref&src=s&origin=recordpageen_HK
dc.identifier.issue6en_HK
dc.identifier.isiWOS:000247924600005-
dc.identifier.citeulike1407844-

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