scholarly journals A New Proposal for Galactic Dark Matter: Effect of f(T) Gravity

2013 ◽  
Vol 53 (2) ◽  
pp. 370-379 ◽  
Author(s):  
Farook Rahaman ◽  
Ritabrata Biswas ◽  
Hafiza Ismat Fatima ◽  
Nasarul Islam
Author(s):  
Engel Roza

It is shown that the Lambda component in the cosmological Lambda-CDM model can be conceived as vacuum energy, consisting of gravitational particles subject to Heisenberg’s energy-time uncertainty. These particles can be modelled as elementary polarisable Dirac-type dipoles (“darks”) in a fluidal space at thermodynamic equilibrium, with spins that are subject to the Bekenstein-Hawking entropy. Around the baryonic kernels, uniformly distributed in the universe, the spins are polarized, thereby invoking an increase of the effective gravitational strength of the kernels. It explains the dark matter effect to the extent that the numerical value of Milgrom’s acceleration constant can be assessed by theory. Non-polarized vacuum particles beyond the baryonic kernels compose the dark energy. The result is a quantum mechanical interpretation of gravity in terms of quantitatively established shares in baryonic matter, dark matter and dark energy, which correspond with the values of the Lambda-CDM model..


1999 ◽  
Vol 513 (2) ◽  
pp. L103-L106 ◽  
Author(s):  
G. Chabrier

2009 ◽  
Vol 18 (12) ◽  
pp. 1903-1912 ◽  
Author(s):  
I. B. KHRIPLOVICH ◽  
D. L. SHEPELYANSKY

We study the capture of galactic dark matter by the solar system. The effect is due to the gravitational three-body interaction between the sun, one of the planets, and a dark matter particle. The analytical estimate for the capture cross-section is derived and the upper and lower bounds for the total mass of the captured dark matter particles are found. The estimates for their density are less reliable. The most optimistic of them gives an enhancement of dark matter density by about three orders of magnitudes compared to its value in our galaxy. However, even this optimistic value remains below the best present observational upper limits by about two orders of magnitude.


2006 ◽  
Vol 645 (2) ◽  
pp. 1001-1011 ◽  
Author(s):  
Francisco Prada ◽  
Anatoly A. Klypin ◽  
Eduardo Simonneau ◽  
Juan Betancort‐Rijo ◽  
Santiago Patiri ◽  
...  

2019 ◽  
Vol 487 (3) ◽  
pp. 4025-4036 ◽  
Author(s):  
O Contigiani ◽  
E M Rossi ◽  
T Marchetti

2019 ◽  
Vol 14 (S353) ◽  
pp. 96-100
Author(s):  
Kohei Hattori ◽  
Monica Valluri

AbstractA recently discovered young, high-velocity giant star J01020100-7122208 is a good candidate of hypervelocity star ejected from the Galactic center, although it has a bound orbit. If we assume that this star was ejected from the Galactic center, it can be used to constrain the Galactic potential, because the deviation of its orbit from a purely radial orbit informs us of the torque that this star has received. Based on this assumption, we estimate the flattening of the Galactic dark matter halo by using the Gaia DR2 data and the circular velocity data. Our Bayesian analysis shows that the orbit of J01020100-7122208 favors a prolate halo within ~ 10 kpc from the Galactic center. The posterior distribution of the density flattening q shows a broad distribution at q ≳ 1 and peaks at q ≃ 1.5. Also, 98.5% of the posterior distribution is located at q > 1, highly disfavoring an oblate halo.


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