English
Related papers

Related papers: A late time accelerated FRW model with scalar and …

200 papers

It has been noticed that for a large class of cosmological models, the gauge fixing of the time-reparametrization invariance does not completely fix the clock. Instead, the system enjoys a surprising residual Noether symmetry under a…

General Relativity and Quantum Cosmology · Physics 2021-12-15 Jibril Ben Achour

To understand mechanisms leading to inflation and late acceleration of the Universe it is important to see how one or a set of quantum fields may evolve such that the classical energy-momentum tensor behave similar to a cosmological…

General Relativity and Quantum Cosmology · Physics 2018-07-17 Houri Ziaeepour

We extend the concept of quintessence to a flat nonminimally coupled scalar - tensor theories of gravity. By means of Noether's symmetries for the cosmological pointlike Lagrangian L, it is possible to exhibit exact solutions for a class of…

High Energy Physics - Theory · Physics 2009-09-25 R. de Ritis , A. A. Marino , C. Rubano , P. Scudellaro

We consider an Einstein-aether type Lorentz-violating theory of gravity in which the aether vector field $V_{\mu }$ is represented as the gradient of a scalar field $\phi $, $V_{\mu }=\nabla _{\mu }\phi $. A self interacting potential for…

General Relativity and Quantum Cosmology · Physics 2014-10-08 Zahra Haghani , Tiberiu Harko , Hamid Reza Sepangi , Shahab Shahidi

In this work we study a general vector-tensor model of dark energy with a Gauss-Bonnet term coupled to a vector field and without explicit potential terms. Considering a spatially flat FRW type universe and a vector field without spatial…

High Energy Physics - Theory · Physics 2016-01-05 A. Oliveros , Enzo L. Solis , Mario A. Acero

We implement a conformal time scale factor duality for Friedmann-Robertson-Walker cosmological models, which is consistent with the weak energy condition. The requirement for self-duality determines the equations of state for a broad class…

High Energy Physics - Theory · Physics 2017-03-15 U. Camara dS , A. A. Lima , G. M. Sotkov

We discuss the relationship between the Noether point symmetries of the geodesic Lagrangian, in a (pseudo)Riemannian manifold, with the elements of the Homothetic algebra of the space. We observe that the classification problem of the…

General Relativity and Quantum Cosmology · Physics 2015-11-25 A. Paliathanasis , K. Krishnakumar , P. G. L. Leach

We present an explicit numerical implementation of the Friedmann equations to model the expansion of the Universe in spatially flat, homogeneous and isotropic Friedmann-Lemaitre-Robertson-Walker (FLRW) cosmologies. Using cosmological…

We provide a detailed analysis of Friedmann-Robertson-Walker universes in a wide range of scalar-tensor theories of gravity. We apply solution-generating methods to three parametrised classes of scalar-tensor theory which lead naturally to…

General Relativity and Quantum Cosmology · Physics 2009-10-28 John D. Barrow , Paul Parsons

In this paper, we study the model of the late universe with the homogeneous, isotropic and flat Friedmann-Robertson-Walker metric, where the source of the gravitational field is based on the fermion and boson field, with the Maxwell term…

General Relativity and Quantum Cosmology · Physics 2020-07-13 O. Razina , P. Tsyba , B. Meirbekov , R. Myrzakulov

The cosmological solutions of the non-minimal $ Y (R)F^2 $ theory which are compatible with FRW space-time are investigated. In order to avoid the isotropy violation of a vector field, it can be considered that the presence of a triplet of…

General Relativity and Quantum Cosmology · Physics 2019-12-24 Özcan Sert

The paper deals with cosmological solutions describing different phases of the Universe for the homogeneous and isotropic FLRW model of the Universe with torsion. Normally, torsion field is not suitable for maximally symmetric space time…

General Relativity and Quantum Cosmology · Physics 2020-10-30 Akash Bose , Subenoy Chakraborty

In this letter, cosmology of a simple NMDC gravity with $\xi R \phi_{,\mu}\phi^{,\mu}$ term and a free kinetic term is considered in flat geometry and in presence of dust matter. A logarithm field transformation $\phi' = \mu \ln \phi$ is…

General Relativity and Quantum Cosmology · Physics 2017-08-22 Burin Gumjudpai , Yuttana Jawralee , Narakorn Kaewkhao

We summarize the use of Noether symmetries in Minisuperspace Quantum Cosmology. In particular, we consider minisuperspace models, showing that the existence of conserved quantities gives selection rules that allow to recover classical…

General Relativity and Quantum Cosmology · Physics 2013-08-07 Salvatore Capozziello , Mariafelicia De Laurentis

We construct gravitational modifications that go beyond Horndeski, namely theories with extended nonminimal derivative couplings, in which the coefficient functions depend not only on the scalar field but also on its kinetic energy. Such…

General Relativity and Quantum Cosmology · Physics 2017-03-01 Tiberiu Harko , Francisco S. N. Lobo , Emmanuel N. Saridakis , Minas Tsoukalas

We describe scalar-bimetric theories where the dynamics of the Universe are governed by two separate metrics, each with an Einstein-Hilbert term. In this setting, the baryonic and dark matter components of the Universe couple to metrics…

General Relativity and Quantum Cosmology · Physics 2018-10-09 Philippe Brax , Patrick Valageas

In this article, we study a flat homogeneous FLRW model in Lyra geometry which is described by a time-dependent displacement vector. We consider an appropriate parametrization of the energy density of scalar field $ \rho_\phi $ in terms of…

General Relativity and Quantum Cosmology · Physics 2023-04-04 J. K. Singh , Shaily , Shri Ram , Joao R. L. Santos , Jéferson A. S. Fortunato

In the present study, we investigate the interaction between dark energy and dark matter, particularly emphasizing the effects of curvature in the realm of Friedmann-Lemaitre-Robertson-Walker (FLRW) space-time. We examine the system by…

General Relativity and Quantum Cosmology · Physics 2023-07-07 Trupti Patil , Sukanta Panda

In this work, we examine solutions of the system of equations obtained by applying the Noether gauge symmetry (NGS) and its conserved quantity for the standard general relativity (GR) and the non-minimal derivative coupling (NMDC)…

General Relativity and Quantum Cosmology · Physics 2022-06-27 Muhammadsorfee Dolohtahe , Watcharakorn Srikom , Phongpichit Channuie , Narakorn Kaewkhao

We develop the $n$-dimensional cosmology for $f(\mathcal{G})$ gravity, where $\mathcal{G}$ is the \emph{Gauss-Bonnet} topological invariant. Specifically, by the so-called Noether Symmetry Approach, we select $f(\mathcal{G})\simeq…

General Relativity and Quantum Cosmology · Physics 2021-11-29 Francesco Bajardi , Salvatore Capozziello
‹ Prev 1 8 9 10 Next ›