scholarly journals Possible formation of wormholes from dark matter in an isothermal galactic halo and void

2019 ◽  
Vol 34 (23) ◽  
pp. 1950188
Author(s):  
Nayan Sarkar ◽  
Susmita Sarkar ◽  
Farook Rahaman ◽  
P. K. F. Kuhfittig ◽  
G. S. Khadekar
Keyword(s):  
Dark Matter ◽  
Galactic Halo ◽  
Energy Condition ◽  
Null Energy Condition ◽  
Galactic Rotation ◽  
Einstein Field Equations ◽  
Field Equations ◽  
Rotation Curves ◽  
Galactic Rotation Curves ◽  
Traversable Wormholes

It is well-known that traversable wormholes are valid solutions of the Einstein field equations, but these structures can only be maintained by violating the null energy condition. In this paper, we have obtained such wormhole solutions in an isothermal galactic halo, as well as in a void. We have shown that the null energy condition is violated, with the help of a suitable redshift function obtained from flat galactic rotation curves.

scholarly journals Self-Interacting Dark Matter Can Explain Diverse Galactic Rotation Curves

2017 ◽  
Vol 119 (11) ◽  
Author(s):  
Ayuki Kamada ◽  
Manoj Kaplinghat ◽  
Andrew B. Pace ◽  
Hai-Bo Yu
Keyword(s):  
Dark Matter ◽  
Galactic Rotation ◽  
Rotation Curves ◽  
Galactic Rotation Curves

scholarly journals TESTING MONDian DARK MATTER WITH GALACTIC ROTATION CURVES

2014 ◽  
Vol 793 (1) ◽  
pp. 41 ◽  
Author(s):  
Doug Edmonds ◽  
Duncan Farrah ◽  
Chiu Man Ho ◽  
Djordje Minic ◽  
Y. Jack Ng ◽  
...  
Keyword(s):  
Dark Matter ◽  
Galactic Rotation ◽  
Rotation Curves ◽  
Galactic Rotation Curves

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.

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