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We investigate the behaviour of the skewness parameters for an anisotropic universe in the framework of General Relativity. Non interacting dark energy is considered in presence of electromagnetic field. A time varying deceleration…

General Physics · Physics 2022-07-19 B. Mishra , Pratik P Ray , S. K. Tripathy , Kazuharu Bamba

If the dark energy equation of state is anisotropic, the expansion rate of the universe becomes direction-dependent at late times. We show that such models are not only cosmologically viable but that they could explain some of the observed…

Astrophysics · Physics 2010-11-11 Tomi Koivisto , David F. Mota

Spatially homogeneous and anisotropic Bianchi type $VI_0$ cosmological models with cosmological constant are investigated in the presence of anisotropic dark energy. We examine the effects of electromagnetic field on the dynamics of the…

General Relativity and Quantum Cosmology · Physics 2010-11-24 M. Sharif , M. Zubair

In this paper, we have derived the field equations in an extended theory of gravity in an anisotropic space time background and in the presence of magnetic field. The physical and geometrical parameters of the models are determined with…

General Relativity and Quantum Cosmology · Physics 2022-07-19 Sankarsan Tarai , Fakhereh Md. Esmaeili , B. Mishra , S. K. Tripathy

We present a model where a non-conventional scalar field may act like dark energy leading to cosmic acceleration. The latter is driven by an appropriate field configuration, which result in an effective cosmological constant. The potential…

High Energy Physics - Theory · Physics 2009-11-11 Alex Kehagias

In this work, we study tracker phantom dark energy models with a general parameterization of the scalar potentials. Our analysis also considers the scenario of having both phantom field and the cosmological constant as the dark energy…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-18 Francisco X. Linares Cedeño , Nandan Roy , L. Arturo Ureña-López

We discuss how a cosmological magnetic field could affect the expansion of the universe, through its interaction with the spacetime geometry. The tension of the field lines means that the magneto-curvature coupling tends to accelerate…

Astrophysics · Physics 2009-10-31 D. R. Matravers , C. G. Tsagas

Observational evidence indicating that the expansion of the universe is accelerating has surprised cosmologists in recent years. Cosmological models have sought to explain this acceleration by incorporating `dark energy', of which the…

Astrophysics · Physics 2010-03-26 Luke Barnes , Matthew J. Francis , Geraint F. Lewis , Eric V. Linder

In view of late-time cosmic acceleration, a dark energy cosmological model is revisited wherein Einstein's cosmological constant is considered as a candidate of dark energy. Exact solution of Einstein field equations (EFEs) is derived in a…

General Relativity and Quantum Cosmology · Physics 2019-11-22 S. K. J. Pacif , Md Salahuddin Khan , L. K. Paikroy , Shalini Singh

We argue that dark energy with multiple fields is theoretically well-motivated and predicts distinct observational signatures, in particular when cosmic acceleration takes place along a trajectory that is highly non-geodesic in field space.…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-11 Yashar Akrami , Misao Sasaki , Adam R. Solomon , Valeri Vardanyan

In this paper, we have studied an interacting dark energy model. We have assumed the gravitational interaction between the matter fields i.e. between barotropic fluid and the dark energy. The dark energy evolution within the framework of…

General Relativity and Quantum Cosmology · Physics 2023-04-03 Keshav Ram Mishra , Shibesh Kumar Jas Pacif , Rajesh Kumar , Kazuharu Bamba

Dark matter, the major component of the matter content of the Universe, played a significant role at early stages during structure formation. But at present the Universe is dark energy dominated as well as accelerating. Here, the presence…

Astrophysics · Physics 2013-09-17 Saibal Ray , Utpal Mukhopadhyay , Farook Rahaman , Ruby Sarkar

We study cosmological models with anisotropy in expansion rates in the context of the recent observations predicting an accelerating universe. In the absence of any anisotropy in the cosmic fluid, it is shown that the role of skewness in…

General Relativity and Quantum Cosmology · Physics 2015-06-22 S. K. Tripathy

I review a class of nonlocally modified gravity models which were proposed to explain the current phase of cosmic acceleration without dark energy. Among the topics considered are deriving causal and conserved field equations, adjusting the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 R. P. Woodard

The consensus of opinion in cosmology is that the Universe is currently undergoing a period of accelerated expansion. With current and proposed high precision experiments it offers the hope of being able to discriminate between the two…

Astrophysics · Physics 2011-02-09 P. S. Corasaniti , E. J. Copeland

We present cosmological perturbation theory in neutrino probe interacting dark-energy models, and calculate cosmic microwave background anisotropies and matter power spectrum. In these models, the evolution of the mass of neutrinos is…

High Energy Physics - Phenomenology · Physics 2008-11-26 Yong-Yeon Keum

We study the minimally and non-minimally coupled scalar field models as possible alternatives for dark energy, the mysterious energy component that is driving the accelerated expansion of the universe. After discussing the dynamics at both…

General Relativity and Quantum Cosmology · Physics 2019-12-03 Zahra Davari , Valerio Marra , Mohammad Malekjani

We study CMB constraints on a model with a cosmological constant and a fraction of dark matter non-minimally coupled to a massless scalar field. In this scenario, there is an extra gravity-like fifth force which can affect the evolution of…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-09 Sophie C. F. Morris , Anne M. Green

It has been recently proposed that the presence of a temporal electromagnetic field on cosmological scales could explain the phase of accelerated expansion that the universe is currently undergoing. The field contributes as a cosmological…

General Physics · Physics 2009-11-13 Jose Beltran Jimenez , Tomi S. Koivisto , Antonio L. Maroto , David F. Mota

A cosmological model is proposed for the current Universe consisted of non-interacting baryonic matter and interacting dark components. The dark energy and dark matter are coupled through their effective barotropic indexes, which are…

Astrophysics · Physics 2009-06-15 Luis P. Chimento , Monica Forte , Gilberto M. Kremer
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