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Related papers: Bulk viscous cosmology: statefinder and entropy

200 papers

We study the bulk flow of the local universe using Type Ia supernova data by considering a class of cosmological model which is spatially flat,(FRW) space-times and contains cold dark matter and $Q$ component (QCDM models) of the fluid as a…

Cosmology and Nongalactic Astrophysics · Physics 2022-05-31 A. Salehi , M. Yarahmadi , S. Fathi

The coming few years are likely to witness a dramatic increase in high quality Sn data as current surveys add more high redshift supernovae to their inventory and as newer and deeper supernova experiments become operational. Given the…

Astrophysics · Physics 2008-11-26 Ujjaini Alam , Varun Sahni , Tarun Deep Saini , A. A. Starobinsky

We study the evolution of the configuration entropy for different combinations of $\Omega_{m0}$ and $\Omega_{\Lambda0}$ in the flat $\Lambda$CDM universe and find that the cosmological constant plays a decisive role in controlling the…

Cosmology and Nongalactic Astrophysics · Physics 2019-03-06 Biswajit Pandey , Biswajit Das

In the present work, we study a cosmological model composed of a viscous dark matter interacting with decaying vacuum energy in a spatially flat Universe. In the first part, we find the analytical solution of different cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2024-05-27 Vinita Khatri , C. P. Singh , Milan Srivastava

Bulk viscosity in cold dark matter is an appealing feature that introduces distinctive phenomenological effects in the cosmological setting as compared to the $\Lambda$CDM model. Under this view, we propose a general parametrization of the…

General Relativity and Quantum Cosmology · Physics 2023-08-24 Gabriel Gómez , Guillermo Palma , Ángel Rincón , Norman Cruz , Esteban González

Conformally flat tilted Bianchi type V cosmological models in presence of a bulk viscous fluid and heat flow are investigated. The coefficient of bulk viscosity is assumed to be a power function of mass density. The cosmological constant is…

General Relativity and Quantum Cosmology · Physics 2008-07-30 Anirudh Pradhan , S. K. Srivastav

Statefinder diagnostic is a convenient method that can differentiate between the various dark energy models. In this article, we analyze the statefinder parameters in symmetric teleparallel cosmology. The $f(Q)$ gravity theory is an…

General Relativity and Quantum Cosmology · Physics 2022-06-27 Raja Solanki , P. K. Sahoo

Recent studies indicate that, near equilibrium condition could not be maintained for bulk viscous matter models during the accelerated expansion of the universe in the context of Einstein's gravity, without including the cosmological…

General Relativity and Quantum Cosmology · Physics 2023-03-28 Vishnu A Pai , Titus K Mathew

Extending the standard $\Lambda$CDM model by considering dissipative effects within a causal viscous framework, and obtaining an analytical solution for the Hubble parameter remains a challenge in the literature. In this work, we resolve…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-29 Vishnu A Pai , Sarath N , Titus K Mathew

We study non-viscous and viscous holographic dark energy models for a homogeneous and isotropic flat Friedmann-Robertson-Walker Universe in $f(R,T)$ gravity. We find that the Hubble horizon as an IR cut-off is suitable for both the models…

General Relativity and Quantum Cosmology · Physics 2015-10-15 C. P. Singh , Pankaj Kumar

We study the statefinder parameters of a cosmological model based on scale-dependent gravity. The effective Einstein field equations come from an average effective action. From the dynamical system, we derive analytical expressions that…

General Relativity and Quantum Cosmology · Physics 2022-05-12 Pedro D. Alvarez , Benjamin Koch , Cristobal Laporte , Felipe Canales , Angel Rincon

The objective of the present work is to study a cosmological model for a spatially flat Universe whose constituents are a dark energy field and a matter field which includes baryons and dark matter. The constituents are supposed to be in…

General Relativity and Quantum Cosmology · Physics 2013-09-13 Gilberto M. Kremer , Octavio A. S. Sobreiro

We apply the Statefinder diagnostic to the Modified Polytropic Cardassian Universe in this work. We find that the Statefinder diagnostic is quite effective to distinguish Cardassian models from a series of other cosmological models. The…

Astrophysics · Physics 2008-11-26 Ze-Long Yi , Tong-Jie Zhang

We revise the conditions for the physical viability of a cosmological model in which dark matter has bulk viscosity and also interacts with dark energy. We have also included radiation and baryonic matter components; all matter components…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Arturo Avelino , Yoelsy Leyva , L. Arturo Urena-Lopez

The irrotational Bianchi V cosmological model under the influence of both shear and bulk viscosity, together with heat flux, has been studied. Exact solutions for the model are obtained with three physically viable assumptions. The first…

General Relativity and Quantum Cosmology · Physics 2019-12-09 A. Banerjee , Abhik Kumar Sanyal

A generalized dynamical equation for the scale factor of the universe is proposed to describe the cosmological evolution, of which the $\Lambda$CDM model is a special case. It also provides a general example to show the equivalence of the…

Astrophysics · Physics 2009-11-11 J. Ren , X. H. Meng

The dynamical system behaviour and thermal evolution of a homogeneous and isotropic dissipative universe are analyzed. The dissipation is driven by the bulk viscosity $\xi = \alpha \rho^s $ and the evolution of bulk viscous pressure is…

General Relativity and Quantum Cosmology · Physics 2020-03-11 Jerin Mohan N D , Krishna P B , Athira Sasidharan , Titus K Mathew

We study particle production and the corresponding entropy increase in the context of cosmology with dynamical vacuum. We focus on the particular form that has been called "running vacuum model" (RVM), which is known to furnish a successful…

General Relativity and Quantum Cosmology · Physics 2020-02-14 Joan Sola , Hao Yu

The full causal M\"uller-Israel-Stewart (MIS) theory of dissipative processes in relativistic fluids is applied to a flat, homogeneous and isotropic universe with bulk viscosity. It is clarified in which sense the so called truncated…

Astrophysics · Physics 2008-11-26 Winfried Zimdahl

We have analyzed a nonsingular model with a variable cosmological term following the Carvalho {\it et al}. ansatz. The model was shown to approximate to the model of Freese {\it et al}. in one direction and to the \"{O}zer-Taha in the…

General Relativity and Quantum Cosmology · Physics 2017-06-15 Arbab I. Arbab