English
Related papers

Related papers: Anisotropic dark energy model with a hybrid scale …

200 papers

A general formalism to investigate Bianchi type $VI_h$ universes is developed in an extended theory of gravity. A minimally coupled geometry and matter field is considered with a rescaled function of $f(R,T)$ substituted in place of the…

General Physics · Physics 2018-03-28 B. Mishra , S. K. Tripathy , Sankarsan Tarai

A new class of a spatially homogeneous and anisotropic Bianchi type-I cosmological models of the universe for perfect fluid distribution within the framework of scalar-tensor theory of gravitation proposed by Saez and Ballester (Phys. Lett.…

General Physics · Physics 2012-11-15 Anirudh Pradhan , Ajay Kumar Singh , H. Amirhashchi

We investigate a unified dark-energy scenario based on the combined effects of Barrow entropy corrections and the QCD ghost mechanism, referred to as the BH--QCDGDE model. The dark-energy density is constructed in a generalized holographic…

The cosmological principle asserts that on sufficiently large scales the Universe is homogeneous and isotropic on spatial slices. To deviate from this principle requires a departure from the FLRW ansatz. In this paper we analyze the…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-23 Andrei Constantin , Thomas R. Harvey , Sebastian von Hausegger , Andre Lukas

A spatially homogeneous and anisotropic Bianchi type V cosmological model of the universe for perfect fluid within the framework of Scale covariant theory of gravitation proposed by Canuto et al., is studied in view of a variable…

General Physics · Physics 2017-04-13 Mohd. Zeyauddin , C. V. Rao

The present study deals with spatially homogeneous and anisotropic Bianchi-I cosmological model representing massive strings. The energy-momentum tensor, as formulated by Letelier (Phys. Rev. D 28: 2414, 1983) has been used to construct…

General Physics · Physics 2014-03-11 Chanchal Chawla , R. K. Mishra , Anirudh Pradhan

We study dynamical condensation process in a holographic superconductor model with anisotropy. The time-dependent numerical solution is constructed for the Einstein-Maxwell-dilaton theory with complex scalar in asymptotic AdS spacetime. The…

High Energy Physics - Theory · Physics 2014-09-17 Xiaojian Bai , Bum-Hoon Lee , Miok Park , Khimphun Sunly

A cosmological model with anisotropic dark energy is analyzed. The amount of deviation from isotropy of the equation of state of dark energy, the skewness \delta, generates an anisotropization of the large-scale geometry of the Universe,…

Cosmology and Nongalactic Astrophysics · Physics 2011-06-28 L. Campanelli , P. Cea , G. L. Fogli , L. Tedesco

We study dynamical dark energy models that allow for general late time behaviour while admitting non-phantom dynamics at early times, including thawing, scaling$+$thawing, and effective fluid extensions. Using current cosmological data, we…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-24 Sk. Sohail , Sonej Alam , Md. Wali Hossain

A diffuse matter filled Type V Universe is studied. The anisotropic behaviour, the distortion caused to the CMBR and the parameter region allowed by present cosmological bounds are examined. It is shown how the overall sky pattern of…

General Relativity and Quantum Cosmology · Physics 2009-10-31 T. Christodoulakis , G. Kofinas , Vasilios Zarikas

The present study deals with spatially homogeneous and totally anisotropic Bianchi type V cosmological model in presence of bulk viscous fluid source with time dependent gravitational constant G and cosmological term Lambda. The coefficient…

General Relativity and Quantum Cosmology · Physics 2022-04-22 Nawsad Ali

We derive a model of dark energy which evolves with time via the scale factor. The equation of state $\omega=(1-2\alpha)/(1+2\alpha)$ is studied as a function of a parameter $\alpha$ introduced in this model. In addition to the recent…

General Relativity and Quantum Cosmology · Physics 2017-06-20 Hemza Azri , A. Bounames

Anisotropic cosmological models are constructed in $f(R,T)$ gravity theory to investigate the dynamics of universe concerning the late time cosmic acceleration. Using a more general and simple approach, the effect of the coupling constant…

General Physics · Physics 2018-10-05 B. Mishra , Sankarsan Tarai , S. K. Tripathy

In a recent article, Kleidis and Spyrou (2015) proposed that both dark matter (DM) and dark energy (DE) can be treated as a single component, if accommodated in the context of a polytropic DM fluid with thermodynamical content. Depending…

Cosmology and Nongalactic Astrophysics · Physics 2017-10-25 Kostas Kleidis , Nikolaos K. Spyrou

In order to understand the nature of the accelerating expansion of the late-time universe, it is important to experimentally determine whether dark energy is a cosmological constant or dynamical in nature. If dark energy already exists…

Cosmology and Nongalactic Astrophysics · Physics 2019-04-02 Chien-Ting Chen , Pisin Chen

Wide area cosmological surveys enable investigation of whether dark energy properties are the same in different directions on the sky. Cosmic microwave background observations strongly restrict any dynamical effects from anisotropy, in an…

Cosmology and Nongalactic Astrophysics · Physics 2013-02-05 Stephen A. Appleby , Eric V. Linder

We investigate the cosmological reconstruction in anisotropic universe for both homogeneous and inhomogeneous content of the universe. Special attention is attached to three interesting cases: Bianchi type-I, Bianchi type-III and…

General Relativity and Quantum Cosmology · Physics 2012-11-29 M. E. Rodrigues , M. J. S. Houndjo , D. Saez-Gomez , F. Rahaman

We investigate Dark Energy by associating it with vacuum energy or Cosmological constant ${\Lambda}$ which is taken to be dynamic in nature. Our approach is phenomenological and falls within the domain of variable-$\Lambda$ Cosmology.…

Cosmology and Nongalactic Astrophysics · Physics 2022-02-08 Arkajit Aich

The dark sector of the Universe need not be completely separable into distinct dark matter and dark energy components. We consider a model of early dark energy in which the dark energy mimics a dark matter component in both evolution and…

Cosmology and Nongalactic Astrophysics · Physics 2014-09-05 Jannis Bielefeld , Robert R. Caldwell , Eric V. Linder

Simple models are constructed for "acceleressence" dark energy: the latent heat of a phase transition occurring in a hidden sector governed by the seesaw mass scale v^2/M_Pl, where v is the electroweak scale and M_Pl the gravitational mass…

Astrophysics · Physics 2009-09-29 Z. Chacko , Lawrence J. Hall , Yasunori Nomura