scholarly journals Rotation curves of rotating Galactic Bose-Einstein condensate dark matter halos

2014 ◽  
Vol 89 (6) ◽  
Author(s):  
F. S. Guzmán ◽  
F. D. Lora-Clavijo ◽  
J. J. González-Avilés ◽  
F. J. Rivera-Paleo
Keyword(s):  
Dark Matter ◽  
Einstein Condensate ◽  
Dark Matter Halos ◽  
Rotation Curves ◽  
Bose Einstein Condensate ◽  
Bose Einstein

scholarly journals DARK MATTER AXIONS

2010 ◽  
Vol 25 (02n03) ◽  
pp. 554-563 ◽  
Author(s):  
P. SIKIVIE
Keyword(s):  
Dark Matter ◽  
Particle Physics ◽  
Cold Dark Matter ◽  
Einstein Condensate ◽  
Dark Matter Halos ◽  
Linear Regime ◽  
Bose Einstein Condensate ◽  
Invisible Axion ◽  
Bose Einstein ◽  
The Universe

The hypothesis of an 'invisible' axion was made by Misha Shifman and others, approximately thirty years ago. It has turned out to be an unusually fruitful idea, crossing boundaries between particle physics, astrophysics and cosmology. An axion with mass of order 10-5 eV (with large uncertainties) is one of the leading candidates for the dark matter of the universe. It was found recently that dark matter axions thermalize and form a Bose-Einstein condensate (BEC). Because they form a BEC, axions differ from ordinary cold dark matter (CDM) in the non-linear regime of structure formation and upon entering the horizon. Axion BEC provides a mechanism for the production of net overall rotation in dark matter halos, and for the alignment of cosmic microwave anisotropy multipoles. Because there is evidence for these phenomena, unexplained with ordinary CDM, an argument can be made that the dark matter is axions.

scholarly journals Galaxy Rotation Curves in the µ-Deformation Based Approach to Dark Matter

2019 ◽  
Vol 64 (11) ◽  
pp. 1042 ◽  
Author(s):  
A. M. Gavrilik ◽  
I. I. Kachurik ◽  
M. V. Khelashvili
Keyword(s):  
Dark Matter ◽  
Physical Meaning ◽  
Deformation Parameter ◽  
Einstein Condensate ◽  
Rotation Curves ◽  
Density Profiles ◽  
Emden Equation ◽  
Bose Einstein Condensate ◽  
Bose Einstein ◽  
Galaxy Rotation Curves

We elaborate further the м-deformation-based approach to the modeling of dark matter, in addition to the earlier proposed use of м-deformed thermodynamics. Herein, we construct м-deformed analogs of the Lane–Emden equation (for density profiles) and find their solutions. Using these, we plot the rotation curves for a number of galaxies. Different curves describing the chosen galaxies are labeled by respective (different) values of the deformation parameter м. As a result, the use of м-deformation leads to the improved agreement with observational data. For all the considered galaxies, the obtained rotation curves (labeled by м) agree better with data, as compared to the well-known Bose–Einstein condensate model results of T. Harko. Besides, for five of the eight cases of galaxies, we find a better picture for rotation curves, than the corresponding Navarro–Frenk–White (NFW) curves. The possible physical meaning of the parameter м basic for this version of м-deformation is briefly discussed.

scholarly journals Testing Bose–Einstein condensate dark matter models with the SPARC galactic rotation curves data

2020 ◽  
Vol 80 (8) ◽  
Author(s):  
Maria Crăciun ◽  
Tiberiu Harko
Keyword(s):  
Dark Matter ◽  
Good Description ◽  
Scattering Length ◽  
Einstein Condensate ◽  
Galactic Rotation ◽  
Rotation Curves ◽  
Galactic Rotation Curves ◽  
Bose Einstein Condensate ◽  
Two Parameters ◽  
Bose Einstein

Abstract The nature of one of the fundamental components of the Universe, dark matter, is still unknown. One interesting possibility is that dark matter could exist in the form of a self-interacting Bose–Einstein Condensate (BEC). The fundamental properties of dark matter in this model are determined by two parameters only, the mass and the scattering length of the particle. In the present study we investigate the properties of the galactic rotation curves in the BEC dark matter model, with quadratic self-interaction, by using 173 galaxies from the recently published Spitzer Photomery & Accurate Rotation Curves (SPARC) data. We fit the theoretical predictions of the rotation curves in the slowly rotating BEC models with the SPARC data by using genetic algorithms. We provide an extensive set of figures of the rotation curves, and we obtain estimates of the relevant astrophysical parameters of the BEC dark matter halos (central density, angular velocity and static radius). The density profiles of the dark matter distribution are also obtained. It turns out that the BEC model gives a good description of the SPARC data. The presence of the condensate dark matter could also provide a solution for the core–cusp problem.

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

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
M. Dwornik ◽  
Z. Keresztes ◽  
E. Kun ◽  
L. Á. Gergely
Keyword(s):  
Dark Matter ◽  
Surface Brightness ◽  
Dwarf Galaxies ◽  
Einstein Condensate ◽  
Galactic Rotation ◽  
Rotation Curves ◽  
Galactic Rotation Curves ◽  
Bose Einstein Condensate ◽  
Bose Einstein ◽  
Lsb Galaxies

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.

scholarly journals Jeans instability and turbulent gravitational collapse of Bose–Einstein condensate dark matter halos

2019 ◽  
Vol 79 (9) ◽  
Author(s):  
Tiberiu Harko
Keyword(s):  
Dark Matter ◽  
Gravitational Collapse ◽  
Separation Of Variables ◽  
Einstein Condensate ◽  
Wave Number ◽  
Radial Coordinate ◽  
Dark Matter Halos ◽  
Bose Einstein Condensate ◽  
Jeans Instability ◽  
Bose Einstein

Abstract We consider the Jeans instability and the gravitational collapse of the rotating Bose–Einstein condensate dark matter halos, described by the zero temperature non-relativistic Gross–Pitaevskii equation, with repulsive interparticle interactions. In the Madelung representation of the wave function, the dynamical evolution of the galactic halos is described by the continuity and the hydrodynamic Euler equations, with the condensed dark matter satisfying a polytropic equation of state with index $$n=1$$n=1. By considering small perturbations of the quantum hydrodynamical equations we obtain the dispersion relation and the Jeans wave number, which includes the effects of the vortices (turbulence), of the quantum pressure and of the quantum potential, respectively. The critical scales above which condensate dark matter collapses (the Jeans radius and mass) are discussed in detail. We also investigate the collapse/expansion of rotating condensed dark matter halos, and we find a family of exact semi-analytical solutions of the hydrodynamic evolution equations, derived by using the method of separation of variables. An approximate first order solution of the fluid flow equations is also obtained. The radial coordinate dependent mass, density and velocity profiles of the collapsing/expanding condensate dark matter halos are obtained by using numerical methods.

scholarly journals Is a Bose–Einstein condensate a good candidate for dark matter? A test with galaxy rotation curves

2020 ◽  
Vol 29 (09) ◽  
pp. 2050063 ◽  
Author(s):  
Elías Castellanos ◽  
Celia Escamilla-Rivera ◽  
Jorge Mastache
Keyword(s):  
Black Hole ◽  
Dark Matter ◽  
Einstein Condensate ◽  
Average Particle ◽  
Rotation Curves ◽  
Massive Scalar Field ◽  
Thomas Fermi ◽  
Bose Einstein Condensate ◽  
Bose Einstein ◽  
Galaxy Rotation Curves

We analyze the rotation curves that correspond to a Bose–Einstein Condensate (BEC)-type halo surrounding a Schwarzschild-type black hole to confront predictions of the model upon observations of galaxy rotation curves. We model the halo as a BEC in terms of a massive scalar field that satisfies a Klein–Gordon equation with a self-interaction term. We also assume that the bosonic cloud is not self-gravitating. To model the halo, we apply a simple form of the Thomas–Fermi approximation that allows us to extract relevant results with a simple and concise procedure. Using galaxy data from a subsample of SPARC data base, we find the best fits of the BEC model by using the Thomas–Fermi approximation and perform a Bayesian statistics analysis to compare the obtained BEC’s scenarios with the Navarro–Frenk–White (NFW) model as pivot model. We find that in the centre of galaxies, we must have a supermassive compact central object, i.e. supermassive black hole, in the range of [Formula: see text] which condensate a boson cloud with average particle mass [Formula: see text] eV and a self-interaction coupling constant [Formula: see text], i.e. the system behaves as a weakly interacting BEC. We compare the BEC model with NFW concluding that in general the BEC model using the Thomas–Fermi approximation is strong enough compared with the NFW fittings. Moreover, we show that BECs still well-fit the galaxy rotation curves and, more importantly, could lead to an understanding of the dark matter nature from first principles.

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