Bose-Einstein Condensate Dark Matter Halos Confronted with Galactic Rotation Curves

Abstract

We present a comparative confrontation of both the Bose-Einstein Condensate (BEC) and the Navarro-Frenk-White (NFW) dark halo models with galactic rotation curves. We employ 6 High Surface Brightness (HSB), 6 Low Surface Brightness (LSB), and 7 dwarf galaxies with rotation curves falling into two classes. In the first class rotational velocities increase with radius over the observed range.The BEC and NFW models give comparable fits for HSB and LSB galaxies of this type, while for dwarf galaxies the fit is significantly better with the BEC model. In the second class the rotational velocity of HSB and LSB galaxies exhibits long flat plateaus, resulting in better fit with the NFW model for HSB galaxies and comparable fits for LSB galaxies. We conclude that due to its central density cusp avoidance the BEC model fits better dwarf galaxy dark matter distribution. Nevertheless it suffers from sharp cutoff in larger galaxies, where the NFW model performs better. The investigated galaxy sample obeys the Tully-Fisher relation, including the particular characteristics exhibited by dwarf galaxies. In both models the fitting enforces a relation between dark matter parameters: the characteristic density and the corresponding characteristic distance scale with an inverse power.

Supplying dark energy from scalar field dark matter

“…which follows from the definition of scalar field energy-momentum tensor (3) in the Schwarzschild background space-time (6), indeed obeys the NFW behavior. After this simple estimations of the scalar BEC galactic DM parameter, which appears to be similar with obtained in the papers [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24], let us consider the larger scale, r d. For these distances galaxies can be imagined as the stationary spherical structures of the DM condensate (22) with some scalar 'tails' in outer galactic region, where the density of DM particle is very low,…”

“…All mentioned small-scale structure anomalies can in principle be resolved if the DM is made up of ultra-light bosons that form a Bose-Einstein Condensate (BEC), i.e. a single coherent macroscopic wave function with long range correlation [8][9][10][11][12][13][14][15][16][17][18][19]. Such kinds of bosons are usually modeled by a scalar field either with or without self-interaction.…”

“…Non-linear equations of this type are known for having soliton-like solutions corresponding to BEC, i.e. under some conditions BEC can be obtained from the Klein-Gordon equation [18,19,[43][44][45].…”

Dark Matter as a Non-Relativistic Bose–Einstein Condensate with Massive Gravitons

“…In this paper, we discuss the possibility of a BEC formed by scalar particles, interacting gravitationally through either the Newton or Yukawa potential. Such a BEC, interacting only through massless gravitons has been previously tested as a viable DM candidate by confronting with galactic rotation curves [30,36].…”

Boson dark matter halos with a dominant noncondensed component

“…Clearly, it is unacceptable for realistic DM halos. The extended BEC DM models take into account available baryonic matter [57], rotation [40,58,59] and temperature [11,60,61] effects. In these approaches R c is identified as a minimum radius corresponding to an inner halo core while the halo can be well larger.…”