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The possibility of determining cosmological parameters on the basis of a wide set of observational data including the Abell-ACO cluster power spectrum and mass function, peculiar velocities of galaxies, the distribution of Ly-$\alpha$…

Astrophysics · Physics 2007-05-23 B. Novosyadlyj , R. Durrer , S. Gottloeber , V. N. Lukash , S. Apunevych

The constraints on the $\Lambda$CDM model from type Ia supernova (SNe Ia) data alone and BAO data alone are similar, so it is worthwhile to compare their constraints on the property of dark energy. We apply the SNLS3 compilation of 472 SNe…

Cosmology and Nongalactic Astrophysics · Physics 2013-04-09 Yungui Gong , Qing Gao , Zong-Hong Zhu

In this paper, the cosmological parameters are determined by applying six cosmological models to fit the magnitude-redshift relation of the Pantheon Sample consisting of 1048 Type Ia supernovae (SNe Ia) in the range of $0.01 < z < 2.26$.…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-18 Peifeng Peng , Nigel Metcalfe

We construct a viable cosmological model based on velocity diffusion of matter particles. In order to ensure the conservation of the total energy-momentum tensor in the presence of diffusion, we include a cosmological scalar field $\phi$…

Cosmology and Nongalactic Astrophysics · Physics 2013-12-04 Simone Calogero , Hermano Velten

The observations of SNIa suggest that we live in the acceleration epoch when the densities of the cosmological constant term and matter are almost equal. This leads to the cosmic coincidence conundrum. As the explanation for this problem we…

Astrophysics · Physics 2008-05-24 Marek Szydlowski

Type Ia supernovae have provided fundamental observational data in the discovery of the late acceleration of the expansion of the Universe in cosmology. However, this analysis has relied on the assumption of a Gaussian distribution for the…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-09 Fabiola Arevalo , Luis Firinguetti , Marcos Peña

We use Gamma Ray Bursts (GRBs) data from Y. Wang (2008) to put additional constraints on a set of cosmological dark energy models based on the holographic principle. GRBs are among the most complex and energetic astrophysical events known…

Cosmology and Nongalactic Astrophysics · Physics 2016-02-12 Alexander Bonilla Rivera , Jairo Ernesto Castillo Hernandez

A simple speed-up cosmology model is proposed to account for the dark energy puzzle. We condense contributions from dark energy and curvature term into one effective parameter in order to reduce parameter degeneracies and to find any…

Astrophysics · Physics 2007-10-10 Xin-He Meng , Meng Su , Zheng Wang

We use higher-redshift gamma-ray burst (GRB), HII starburst galaxy (HIIG), and quasar angular size (QSO-AS) measurements to constrain six spatially flat and non-flat cosmological models. These three sets of cosmological constraints are…

Cosmology and Nongalactic Astrophysics · Physics 2021-01-15 Shulei Cao , Joseph Ryan , Narayan Khadka , Bharat Ratra

In this work, we apply the formalism of dynamical systems to analyze the viability of the $\Lambda$CDM model in a generalized form of the hybrid metric-Palatini gravity theory written in terms of its dynamically equivalent scalar-tensor…

General Relativity and Quantum Cosmology · Physics 2024-09-06 João Luís Rosa

We studied the cosmological constraints on the Galileon gravity obtained from observational data of the growth rate of matter density perturbations, the supernovae Ia (SN Ia), the cosmic microwave background (CMB), and baryon acoustic…

Cosmology and Nongalactic Astrophysics · Physics 2012-07-03 Koichi Hirano , Zen Komiya , Hisato Shirai

The standard relation between the cosmological redshift and cosmic scale factor underlies cosmological inference from virtually all kinds of cosmological observations, leading to the emergence of the LambdaCDM cosmological model. This…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-08 Radosław Wojtak , Francisco Prada

Assessing the consistency of parameter constraints derived from different cosmological probes is an important way to test the validity of the underlying cosmological model. In an earlier work [Nicola et al., 2017], we computed constraints…

Cosmology and Nongalactic Astrophysics · Physics 2017-11-01 Andrina Nicola , Adam Amara , Alexandre Refregier

We use Hubble parameter versus redshift data from Stern, et al(2010) and Gazta\~{n}aga, et al (2009) to place constraints on model parameters of constant and time-evolving dark energy cosmological models. These constraints are consistent…

Cosmology and Nongalactic Astrophysics · Physics 2013-07-12 Yun Chen , Bharat Ratra

There has been recent interest in the cosmological consequences of energy-momentum-powered gravity models, in which the matter side of Einstein's equations is modified by the addition of a term proportional to some power, $n$, of the…

Cosmology and Nongalactic Astrophysics · Physics 2019-05-29 M. C. F. Faria , C. J. A. P. Martins , F. Chiti , B. S. A. Silva

There is an apparent tension between cosmological parameters obtained from {\it Planck} cosmic microwave background radiation observations and that derived from the observed magnitude-redshift relation for the type Ia supernova (SNe Ia).…

Cosmology and Nongalactic Astrophysics · Physics 2013-12-31 Zhengxiang Li , Puxun Wu , Hongwei Yu , Zong-Hong Zhu

The Hubble parameters measured by the DESI DR2 BAO observations show a significant discrepancy from the prediction of the standard cosmological model. This discrepancy, together with the long-discussed Hubble tension, may originate from…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-08 Toshifumi Futamase , Reiki Kojima , Masanori Tomonaga

In this work, we use two gas mass fraction samples of galaxy clusters obtained from their X-ray surface brightness observations jointly with recent $H(z)$ data in a flat $\Lambda$CDM framework to impose limits on cosmic opacity. It is…

Cosmology and Nongalactic Astrophysics · Physics 2021-11-01 R. F. L. Holanda , Kamilla V. R. A. Silva , V. C. Busti

We discuss a class of uniform and isotropic, spatially flat, decaying Lambda cosmologies, in the realm of a model where the gravitation constant G is a function of the cosmological time. Besides the usual de Sitter solution, the models at…

General Relativity and Quantum Cosmology · Physics 2010-03-19 S. Carneiro , J. A. S. Lima

The behavior of the constants, G,c,h,a,e,m and Lambda, considering them as variable, in the framework of a flat cosmological model with FRW symmetries described by a bulk viscous fluid and considering mechanisms of adiabatic matter creation…

General Relativity and Quantum Cosmology · Physics 2014-11-17 J. A. Belinchon