Zobrazeno 1 - 10
of 10
pro vyhledávání: '"Kamal Bora"'
The Hubble constant from galaxy cluster scaling-relation and SNe Ia observations: a consistency test
Autor:
Kamal Bora, R. F. L. Holanda
Publikováno v:
European Physical Journal C: Particles and Fields, Vol 83, Iss 4, Pp 1-8 (2023)
Abstract In this paper, we propose a self-consistent test for a Hubble constant estimate using galaxy cluster and type Ia supernovae (SNe Ia) observations. The approach consists, in a first step, of obtaining the observational value of the galaxy clu
Externí odkaz:
https://doaj.org/article/cc50f3b41c074be6afc5ec3f540db8f4
Publikováno v:
European Physical Journal C: Particles and Fields, Vol 82, Iss 6, Pp 1-10 (2022)
Abstract In this work, we discuss a new method to probe the redshift evolution of the gas depletion factor, i.e. the ratio by which the gas mass fraction of galaxy clusters is depleted with respect to the universal mean of baryon fraction. The datase
Externí odkaz:
https://doaj.org/article/a265ab3db7e948e39b5a0e1b671602fb
Publikováno v:
European Physical Journal C: Particles and Fields, Vol 82, Iss 1, Pp 1-6 (2022)
Abstract In 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 evo
Externí odkaz:
https://doaj.org/article/e0b58fa07d7944ab93a01b280fac7a70
Publikováno v:
European Physical Journal C: Particles and Fields, Vol 81, Iss 7, Pp 1-7 (2021)
Abstract We 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 $$\rho _c(z) \propto (1+z)^{3+\epsilo
Externí odkaz:
https://doaj.org/article/6f234757802840aa955a6bf71eab03f7
A model-independent test of the evolution of gas depletion factor for SPT-SZ and Planck ESZ clusters
Autor:
Kamal Bora, Shantanu Desai
Publikováno v:
European Physical Journal C: Particles and Fields, Vol 81, Iss 4, Pp 1-14 (2021)
Abstract The gas mass fraction in galaxy clusters has been widely used to determine cosmological parameters. This method assumes that the ratio of the cluster gas mass fraction to the cosmic baryon fraction ( $$\gamma (z)$$ γ ( z ) ) is constant as
Externí odkaz:
https://doaj.org/article/a8f75527ebf84a39afc37a9f8b43a330
Publikováno v:
Scopus
Repositório Institucional da UNESP
Universidade Estadual Paulista (UNESP)
instacron:UNESP
Repositório Institucional da UNESP
Universidade Estadual Paulista (UNESP)
instacron:UNESP
In this paper, we implement a new method to test the invariance of the speed of light ($c$) as a function of redshift, by combining the measurements of galaxy cluster gas mass fraction, $H(z)$ from cosmic chronometers, and Type-Ia supernovae (SNe Ia)
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::0bbb2387a595b0516e46ed827b0eaa23
http://arxiv.org/abs/2109.14512
http://arxiv.org/abs/2109.14512
Autor:
Shantanu Desai, Kamal Bora
We carry out a test of the cosmic distance duality relation using a sample of 52 SPT-SZ clusters, along with X-ray measurements from XMM-Newton. To carry out this test, we need an estimate of the luminosity distance ($D_L$) at the redshift of the clu
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::f0c793f4ba15dd1420242869cc9747ec
http://arxiv.org/abs/2104.00974
http://arxiv.org/abs/2104.00974
Publikováno v:
European Physical Journal C: Particles and Fields, Vol 81, Iss 7, Pp 1-7 (2021)
European Physical Journal
European Physical Journal
We 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 $\rho_c(z) \propto (1+z)^{3+\epsilon}$, and th
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::7114217ad1359b1b9bb9fcbe8aed3f56
Autor:
Kamal Bora, Shantanu Desai
We search for a variation of the electromagnetic fine structure constant ($\alpha \equiv e^2/\hbar c$) using a sample of 58 SZ selected clusters in the redshift range ($0.2
Comment: 12 pages, 4 figures
Comment: 12 pages, 4 figures
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::a548bd4ca0f9de70abede8819c9b8f24
http://arxiv.org/abs/2008.10541
http://arxiv.org/abs/2008.10541
Publikováno v:
Journal of Cosmology and Astroparticle Physics. 2021:084
The Einstein equivalence principle in the electromagnetic sector can be violated in modifications of gravity theory generated by a multiplicative coupling of a scalar field to the electromagnetic Lagrangian. In such theories, deviations of the standa
Externí odkaz:
https://explore.openaire.eu/search/publication?articleId=doi_dedup___::46d6efa34180366db968698598f53c82
https://doi.org/10.1088/1475-7516/2021/10/084
https://doi.org/10.1088/1475-7516/2021/10/084