English
Related papers

Related papers: Dark energy and accelerating cosmological evolutio…

200 papers

This study investigates the cosmological implications of $f(R,\Sigma,T)$ gravity by reconstructing the Hubble parameter from a logarithmic parameterization of the $O_m(z)$ diagnostic. Our approach offers a model-independent way to probe the…

General Relativity and Quantum Cosmology · Physics 2026-05-12 N. Myrzakulov , Anirudh Pradhan , Anil Kumar Yadav , S. H. Shekh

The effective evolution of an inhomogeneous universe model in any theory of gravitation may be described in terms of spatially averaged variables. In Einstein's theory, restricting attention to scalar variables, this evolution can be…

General Relativity and Quantum Cosmology · Physics 2010-04-06 Thomas Buchert

In this study one resorts to the phenomenology of models endowed with a non-minimal coupling between matter and geometry, in order to develop a mechanism through which dynamics similar to that due to the presence of dark matter is…

Astrophysics of Galaxies · Physics 2015-05-13 O. Bertolami , J. Paramos

Applying the cosmological principle to Finsler spacetimes, we identify the Lie Algebra of symmetry generators of spatially homogeneous and isotropic Finsler geometries, thus generalising Friedmann-Lema\^{i}tre-Robertson-Walker geometry. In…

General Relativity and Quantum Cosmology · Physics 2020-05-06 Manuel Hohmann , Christian Pfeifer , Nicoleta Voicu

It has recently been shown that the observed Hubble function for cosmological expansion can be fitted accurately back to redshift unity (7.33 Gyr ago) with only one free constant, while neglecting cosmic curvature and mass, using the…

General Physics · Physics 2021-05-26 R. K. Nesbet

Massive particle and antiparticle pair production and oscillation on the horizon form a holographic and massive pair plasma state in the Friedman Universe. Via this state, the Einstein cosmology term (dark energy) interacts with matter and…

General Relativity and Quantum Cosmology · Physics 2024-05-21 She-Sheng Xue

An anisotropic fluid with positive energy density and negative pressures is proposed in the black hole interior. The gravitational field is constant everywhere inside and is given by the horizon surface gravity. Even though the geometry is…

General Relativity and Quantum Cosmology · Physics 2015-05-27 Hristu Culetu

In this paper, after reconstructing the redshift evolution of the Hubble function by adopting Gaussian process techniques, we estimate the best-fit parameters for some flat Friedmann cosmological models based on a Modified Chaplygin Gas…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-28 Muhsin Aljaf , Daniele Gregoris , Martiros Khurshudyan

This paper analyses the cosmological consequences of a modified theory of gravity whose action integral is built from a linear combination of the Ricci scalar $R$ and a quadratic term in the covariant derivative of $R$. The resulting…

General Relativity and Quantum Cosmology · Physics 2015-12-31 R. R. Cuzinatto , C. A. M. de Melo , L. G. Medeiros , P. J. Pompeia

Recently the Chiral Cosmological Model (CCM) coupled to cold dark matter (CDM) has been investigated as $\sigma$CDM model to study the observed accelerated expansion of the Universe. Dark sector fields (as Dark Energy content) coupled to…

General Relativity and Quantum Cosmology · Physics 2015-08-26 Renat R. Abbyazov , Sergey V. Chervon , Volker Müller

We overview a new mechanism whereby classical Riemannian geometry emerges out of the differential structure on quantum spacetime, as extension data for the classical algebra of differential forms. Outcomes for physics include a new formula…

General Relativity and Quantum Cosmology · Physics 2015-06-18 Shahn Majid

The "dark energy" problem is investigated in the framework of the Poincare gauge theory of gravity in 4-dimensional Riemann-Cartan space-time. By using general expression for gravitational Lagrangian homogeneous isotropic cosmological…

General Relativity and Quantum Cosmology · Physics 2007-05-23 A. V. Minkevich , A. S. Garkun , V. I. Kudin

The current standard cosmological model is constructed within the framework of general relativity with a cosmological constant $\Lambda$, which is often associated with dark energy, and phenomenologically explains the accelerated cosmic…

General Relativity and Quantum Cosmology · Physics 2023-06-27 Jiamin Hou , Julian Bautista , Maria Berti , Carolina Cuesta-Lazaro , César Hernández-Aguayo , Tilman Tröster , Jinglan Zheng

In some recent papers, the relations existing between the metric properties of Randers spaces and the conformal geometry of stationary Lorentzian manifolds were discovered and investigated. In this note, we focus on the equality between the…

Differential Geometry · Mathematics 2011-05-24 Erasmo Caponio

The field equations in $f(R)$ gravity derived from the Palatini variational principle and formulated in the Einstein conformal frame yield a cosmological term which varies with time. Moreover, they break the conservation of the…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Nikodem J. Poplawski

We study the cosmological consequences of a recently proposed nonlocal modification of general relativity, obtained by adding a term $m^2R\,\Box^{-2}R$ to the Einstein-Hilbert action. The model has the same number of parameters as…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-16 Yves Dirian , Stefano Foffa , Nima Khosravi , Martin Kunz , Michele Maggiore

In this paper, we have developed a new cosmological model in Einstein's modified gravity theory using two types of modification.(i) Geometrical modification, in which we have used Lyra's geometry in the left hand side of the Einstein field…

General Relativity and Quantum Cosmology · Physics 2019-07-17 Dinesh Chandra Maurya , Rashid Zia

This paper explores the dark energy phenomenon within the context of $f(R,L_m)$ gravity theory. Two specific non-linear $f (R, L_m)$ models are considered: $f(R,L_m)=\frac{R}{2}+L_m^\alpha$ and $f(R,L_m)=\frac{R}{2}+(1+\alpha R)L_m$, where…

Cosmology and Nongalactic Astrophysics · Physics 2023-12-13 S. Myrzakulova , M. Koussour , N. Myrzakulov

Finsler geometry naturally appears in the description of various physical systems. In this review I divide the emergence of Finsler geometry in physics into three categories: as dual description of dispersion relations, as most general…

General Relativity and Quantum Cosmology · Physics 2019-11-01 Christian Pfeifer

A plane symmetric Bianchi-I model is explored in $f(R,T)$ gravity, where $R$ is the Ricci scalar and $T$ is the trace of energy-momentum tensor. The solutions are obtained with the consideration of a specific Hubble parameter which yields a…

General Relativity and Quantum Cosmology · Physics 2020-03-23 Vijay Singh , Aroonkumar Beesham
‹ Prev 1 8 9 10 Next ›