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Related papers: Statefinder analysis of scale-dependent cosmology

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In this paper, we intend to evaluate and analyze the statefinder parameters in $f(T)$ cosmology. Friedmann equation in $f(T)$ model is taken, and the statefinder parameters ${r,s}$ are calculated. We consider a model of $f(T)$ which…

General Physics · Physics 2012-11-13 Mubasher Jamil , Davood Momeni , Ratbay Myrzakulov , Prabir Rudra

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

We use cosmography to present constraints on the kinematics of the Universe without postulating any underlying theoretical model a priori. To this end, we use a Markov Chain Monte Carlo analysis to perform comparisons to the supernova Ia…

Cosmology and Nongalactic Astrophysics · Physics 2013-01-18 Alejandro Aviles , Christine Gruber , Orlando Luongo , Hernando Quevedo

In the present work, we have adopted a kinematic approach for constraining the extended null diagnostic of concordance cosmology, known as the statefinder hierarchy. A Taylor series expansion of the Hubble parameter has been utilised for…

Cosmology and Nongalactic Astrophysics · Physics 2019-01-08 Ankan Mukherjee , Niladri Paul , H. K. Jassal

We introduce a new cosmological diagnostic pair $\lbrace r,s\rbrace$ called Statefinder. The Statefinder is dimensionless and, like the Hubble and deceleration parameters $H(z)$ and $q(z)$, is constructed from the scale factor of the…

Astrophysics · Physics 2011-07-19 Varun Sahni , Tarun Deep Saini , A. A. Starobinsky , Ujjaini Alam

The present work deals with kinematical models of latetime cosmology. It is based on purely phenomenological assumption about the deceleration parameter. The models are confronted to observational data sets of type Ia supernovae distance…

Cosmology and Nongalactic Astrophysics · Physics 2021-03-12 Ankan Mukherjee

On the basis of qualitative theory of differential equations it is shown that dynamic system based on the system of Einstein - Klein - Gordon equations with regard to Friedman Universe has a stable center corresponding to zero values of…

General Relativity and Quantum Cosmology · Physics 2016-09-06 Yurii Ignat'ev

We focus on a series of $f(R)$ gravity theories in Palatini formalism to investigate the probabilities of producing the late-time acceleration for the flat Friedmann-Robertson-Walker (FRW) universe. We apply statefinder diagnostic to these…

General Relativity and Quantum Cosmology · Physics 2020-05-27 Shu-Lei Cao , Song Li , Hao-Ran Yu , Tong-Jie Zhang

We present a cosmological model containing a cosmological constant $\Lambda$ and a component with an inhomogeneous equation of state. We study the form of the inhomogeneous equation of state for which the model exhibits the relaxation of…

General Relativity and Quantum Cosmology · Physics 2008-12-01 Hrvoje Stefancic

Strong lensing provides popular techniques to investigate the mass distribution of intermediate redshift galaxies, testing galaxy evolution and formation scenarios. It especially probes the background cosmic expansion, hence constraining…

Cosmology and Nongalactic Astrophysics · Physics 2015-11-18 Vincenzo F. Cardone , Ester Piedipalumbo , Paolo Scudellaro

Accelerating expansion of the Universe is a great challenge for both physics and cosmology. In light of lacking the convincing theoretical explanation, an effective description of this phenomenon in terms of cosmic equation of state turns…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 M. Biesiada , A. Piorkowska , B. Malec

An exact cosmological solution of Einstein field equations (EFEs) is derived for a dynamical vacuum energy in $f(R,T)$ gravity for Friedmann-Lemaitre-Robertson-Walker (FLRW) space-time. A parametrization of the Hubble parameter is used to…

General Physics · Physics 2018-11-22 Ritika Nagpal , S. K. J. Pacif , J. K. Singh , Kazuharu Bamba , A. Beesham

Field-level inference is emerging as a promising technique for optimally extracting information from cosmological datasets. Indeed, previous analyses have shown field-based inference produces tighter parameter constraints than power…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-04 Supranta S. Boruah , Eduardo Rozo

We give a scalar field description of two dark energy parameterizations, and we analyze in detail its cosmology both at the level of background evolution and at the level of linear perturbations. In particular, we compute the statefinder…

Cosmology and Nongalactic Astrophysics · Physics 2017-08-02 G. Panotopoulos

Dynamical aspects of cosmological model in an extended gravity theory have been investigated in the present work. We have adopted a simplified approach to obtain cosmic features, which in fact requires more involved calculations. A…

General Relativity and Quantum Cosmology · Physics 2021-06-10 B. Mishra , S. K. Tripathy , Sankarsan Tarai

We discuss a mechanism that induces a time-dependent vacuum energy on cosmological scales. It is based on the instability induced renormalization triggered by the low energy quantum fluctuations in a Universe with a positive cosmological…

General Relativity and Quantum Cosmology · Physics 2015-06-03 Alfio Bonanno , Sante Carloni

We have considered a cosmological model of the FRW universe with variable $G$ and $\Lambda$. The solutions have been obtained for flat model with particular form of cosmological constant. The cosmological parameters have also been obtained…

General Relativity and Quantum Cosmology · Physics 2011-03-31 Mubasher Jamil , Ujjal Debnath

We use astrophysical data to shed light on fundamental physics by constraining parametrized theoretical cosmological and gravitational models. Gravitational parameters are those constants that parametrize possible departures from Einstein's…

Astrophysics · Physics 2008-08-18 Yi Mao

The quantization of Einstein-Maxwell theory with a cosmological constant is considered. We obtain all logarithmically divergent terms in the one-loop effective action that involve only the background electromagnetic field. This includes…

High Energy Physics - Theory · Physics 2009-11-06 David J. Toms

Cosmography is a useful tool to constrain cosmological models, in particular dark energy models. In the case of modified theories of gravity, where the equations of motion are generally quite complicated, cosmography can contribute to…

General Relativity and Quantum Cosmology · Physics 2010-12-23 Mariam Bouhmadi-Lopez , Salvatore Capozziello , Vincenzo F. Cardone