scholarly journals A test of the standard dark matter density evolution law using galaxy clusters and cosmic chronometers

2022 ◽  
Vol 82 (1) ◽  
Author(s):  
Kamal Bora ◽  
R. F. L. Holanda ◽  
Shantanu Desai ◽  
S. H. Pereira
Keyword(s):  
Dark Matter ◽  
Galaxy Cluster ◽  
Matter Density ◽  
Density Evolution ◽  
Full Agreement ◽  
Evolution Law ◽  
Dark Matter Density ◽  
The Galaxy ◽  
Mass Fractions ◽  
Frw Metric

AbstractIn this paper, we implement a test of the standard law for the dark matter density evolution as a function of redshift. For this purpose, only a flat universe and the validity of the FRW metric are assumed. A deformed dark matter density evolution law is considered, given by $$\rho _c(z) \propto (1+z)^{3+\epsilon }$$ ρ c ( z ) ∝ ( 1 + z ) 3 + ϵ , and constraints on $$\epsilon $$ ϵ are obtained by combining the galaxy cluster gas mass fractions with cosmic chronometers measurements. We find that $$\epsilon =0$$ ϵ = 0 within 2$$\sigma $$ σ c.l., in full agreement with other recent analyses.

scholarly journals Probing the dark matter density evolution law with large scale structures

2021 ◽  
Vol 81 (7) ◽  
Author(s):  
Kamal Bora ◽  
R. F. L. Holanda ◽  
Shantanu Desai
Keyword(s):  
Dark Matter ◽  
Gravitational Lensing ◽  
Large Scale ◽  
Galaxy Cluster ◽  
Matter Density ◽  
Evolution Law ◽  
Large Scale Structures ◽  
Dark Matter Density ◽  
Scale Structures ◽  
Rule Out

AbstractWe propose a new method to explore a possible departure from the standard time evolution law for the dark matter density. We looked for a violation of this law by using a deformed evolution law, given by $$\rho _c(z) \propto (1+z)^{3+\epsilon }$$ ρ c ( z ) ∝ ( 1 + z ) 3 + ϵ , and then constrain $$\epsilon $$ ϵ . The dataset used for this purpose consists of Strong Gravitational Lensing data obtained from SLOAN Lens ACS, BOSS Emission-line Lens Survey, Strong Legacy Survey SL2S, and SLACS; along with galaxy cluster X-ray gas mass fraction measurements obtained using the Chandra Telescope. Our analyses show that $$\epsilon $$ ϵ is consistent with zero within 1 $$\sigma $$ σ c.l., but the current dataset cannot rule out with high confidence level interacting models of dark matter and dark energy.

scholarly journals Determining the local dark matter density with LAMOST data

2016 ◽  
Vol 458 (4) ◽  
pp. 3839-3850 ◽  
Author(s):  
Qiran Xia ◽  
Chao Liu ◽  
Shude Mao ◽  
Yingyi Song ◽  
Lan Zhang ◽  
...  
Keyword(s):  
Dark Matter ◽  
Matter Density ◽  
Dark Matter Density

scholarly journals Isolated dwarf galaxies: from cuspy to flat dark matter density profiles and metalicity gradients

2010 ◽  
Vol 514 ◽  
pp. A47 ◽  
Author(s):  
S. Pasetto ◽  
E. K. Grebel ◽  
P. Berczik ◽  
R. Spurzem ◽  
W. Dehnen
Keyword(s):  
Dark Matter ◽  
Dwarf Galaxies ◽  
Matter Density ◽  
Density Profiles ◽  
Dark Matter Density

scholarly journals Non-Gaussian inference from non-linear and non-Poisson biased distributed data

2014 ◽  
Vol 10 (S306) ◽  
pp. 258-261
Author(s):  
Metin Ata ◽  
Francisco-Shu Kitaura ◽  
Volker Müller
Keyword(s):  
Dark Matter ◽  
Statistical Inference ◽  
Computer Code ◽  
Matter Density ◽  
Density Field ◽  
Distributed Data ◽  
Dark Matter Density ◽  
Posterior Sampling ◽  
Non Linear ◽  
Non Gaussian

AbstractWe study the statistical inference of the cosmological dark matter density field from non-Gaussian, non-linear and non-Poisson biased distributed tracers. We have implemented a Bayesian posterior sampling computer-code solving this problem and tested it with mock data based onN-body simulations.

scholarly journals NIHAO – IV: core creation and destruction in dark matter density profiles across cosmic time

2016 ◽  
Vol 456 (4) ◽  
pp. 3542-3552 ◽  
Author(s):  
Edouard Tollet ◽  
Andrea V. Macciò ◽  
Aaron A. Dutton ◽  
Greg S. Stinson ◽  
Liang Wang ◽  
...  
Keyword(s):  
Dark Matter ◽  
Cosmic Time ◽  
Matter Density ◽  
Density Profiles ◽  
Dark Matter Density

scholarly journals Measuring the local dark matter density with LAMOST DR5 and Gaia DR2

2020 ◽  
Vol 495 (4) ◽  
pp. 4828-4844 ◽  
Author(s):  
Rui Guo ◽  
Chao Liu ◽  
Shude Mao ◽  
Xiang-Xiang Xue ◽  
R J Long ◽  
...  
Keyword(s):  
Dark Matter ◽  
Azimuthal Angle ◽  
Matter Density ◽  
Dwarf Stars ◽  
Dark Matter Density ◽  
The North ◽  
Vertical Data ◽  
Data Release ◽  
The Difference ◽  
North And South

ABSTRACT We apply the vertical Jeans equation to the kinematics of Milky Way stars in the solar neighbourhood to measure the local dark matter density. More than 90 000 G- and K-type dwarf stars are selected from the cross-matched sample of LAMOST (Large Sky Area Multi-Object Fibre Spectroscopic Telescope) fifth data release and Gaia second data release for our analyses. The mass models applied consist of a single exponential stellar disc, a razor thin gas disc, and a constant dark matter density. We first consider the simplified vertical Jeans equation that ignores the tilt term and assumes a flat rotation curve. Under a Gaussian prior on the total stellar surface density, the local dark matter density inferred from Markov chain Monte Carlo simulations is $0.0133_{-0.0022}^{+0.0024}\ {\rm M}_{\odot }\, {\rm pc}^{-3}$. The local dark matter densities for subsamples in an azimuthal angle range of −10° < ϕ < 5° are consistent within their 1σ errors. However, the northern and southern subsamples show a large discrepancy due to plateaux in the northern and southern vertical velocity dispersion profiles. These plateaux may be the cause of the different estimates of the dark matter density between the north and south. Taking the tilt term into account has little effect on the parameter estimations and does not explain the north and south asymmetry. Taking half of the difference of σz profiles as unknown systematic errors, we then obtain consistent measurements for the northern and southern subsamples. We discuss the influence of the vertical data range, the scale height of the tracer population, the vertical distribution of stars, and the sample size on the uncertainty of the determination of the local dark matter density.

Studying the Patterns of the Universe

2011 ◽  
Vol 20 (2) ◽  
Author(s):  
T. Sepp ◽  
E. Tempel ◽  
M. Gramann ◽  
P. Nurmi ◽  
M. Haupt
Keyword(s):  
Dark Matter ◽  
Galaxy Cluster ◽  
Analytical Models ◽  
Matter Distribution ◽  
Galaxy Groups ◽  
The Galaxy ◽  
Dark Matter Distribution ◽  
Distribution Studies ◽  
The Universe ◽  
Good Agreement

AbstractThe SDSS galaxy catalog is one of the best databases for galaxy distribution studies. The SDSS DR8 data is used to construct the galaxy cluster catalog. We construct the clusters from the calculated luminosity density field and identify denser regions. Around these peak regions we construct galaxy clusters. Another interesting question in cosmology is how observable galaxy structures are connected to underlying dark matter distribution. To study this we compare the SDSS DR7 galaxy group catalog with galaxy groups obtained from the semi-analytical Millennium N-Body simulation. Specifically, we compare the group richness, virial radius, maximum separation and velocity dispersion distributions and find a relatively good agreement between the mock catalog and observations. This strongly supports the idea that the dark matter distribution and galaxies in the semi-analytical models and observations are very closely linked.

scholarly journals Probing a dark matter density spike at the Galactic Center

2014 ◽  
Vol 89 (6) ◽  
Author(s):  
Thomas Lacroix ◽  
Céline Bœhm ◽  
Joseph Silk
Keyword(s):  
Dark Matter ◽  
Galactic Center ◽  
Matter Density ◽  
Dark Matter Density

scholarly journals A new determination of the local dark matter density from the kinematics of K dwarfs

2012 ◽  
Vol 425 (2) ◽  
pp. 1445-1458 ◽  
Author(s):  
Silvia Garbari ◽  
Chao Liu ◽  
Justin I. Read ◽  
George Lake
Keyword(s):  
Dark Matter ◽  
Matter Density ◽  
Dark Matter Density
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