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Related papers: f(R) scalar-tensor cosmology by Noether symmetry

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In the background of homogeneous and isotropic flat FLRW space-time, both classical and quantum cosmology has been studied for teleparallel dark energy (DE) model. Using Noether symmetry analysis, not only the symmetry vector but also the…

General Relativity and Quantum Cosmology · Physics 2024-07-12 Dipankar Laya , Roshni Bhaumik , Sourav Dutta , Subenoy Chakraborty

We derive and solve exactly the Dyer-Roeder equation in a Friedman-Robertson-Walker cosmological model with non zero cosmological constant. To take into account non homogeneous distribution of matter we use the phenomenological clumpiness…

Astrophysics · Physics 2019-06-05 M. Demianski , R. de Ritis , A. A. Marino , E. Piedipalumbo

The purpose of the current article is to present a brief albeit accurate presentation of the main tools used in the study of symmetries of Lagrange equations for holonomic systems and subsequently to show how these tools are applied in the…

General Relativity and Quantum Cosmology · Physics 2018-06-18 Michael Tsamparlis , Andronikos Paliathanasis

We show how the scalar field, a candidate of quintessence, in a proposed model of the scalar-tensor theories of gravity provides a way to understand a small but nonzero cosmological constant as indicated by recent observations. A particular…

General Relativity and Quantum Cosmology · Physics 2009-09-25 Yasunori Fujii

We investigate the cosmological dynamics in a spatially flat Friedmann--Lema\^{\i}tre--Robertson--Walker geometry in scalar-tensor and scalar-torsion theories where the nonminimally coupled scalar field is a complex field. We derive the…

General Relativity and Quantum Cosmology · Physics 2022-11-23 Andronikos Paliathanasis

Exact cosmological solutions are obtained for a five dimensional inhomogeneous fluid distribution along with a Brans-Dicke type of scalar field. The set includes varied forms of matter field including $\rho+p=0$, where p is the 3D isotropic…

General Relativity and Quantum Cosmology · Physics 2009-11-10 D. Panigrahi , Y. Z. Zhang , S. Chatterjee

Swampland conjecture has been recently proposed to connect early time cosmological models with the string landscape, and then to understand if related scalar fields and potentials can come from some fundamental theory in the high energy…

General Relativity and Quantum Cosmology · Physics 2020-11-09 Micol Benetti , Salvatore Capozziello , Leila Lobato Graef

In the present work we investigate the Hojman symmetry in FRW cosmology. In particular, we use the Hojman symmetry to find conserved quantities of particular cosmological models. Next, we study the Hojman symmetry in the scalar-tensor…

General Relativity and Quantum Cosmology · Physics 2016-03-15 Aizhan Myrzakul , Ratbay Myrzakulov

Finding spherically symmetric exact solutions in modified gravity is usually a difficult task. In this paper we use the Noether's symmetry approach for a modified Teleparallel theory of gravity labelled as $f(T,B)$ gravity where $T$ is the…

General Relativity and Quantum Cosmology · Physics 2019-12-02 Sebastian Bahamonde , Ugur Camci

A new symmetry for Newtonian Dynamics is analyzed, this corresponds to going to an accelerated frame, which introduces a constant gravitational field into the system and subsequently. We consider the addition of a linear contribution to the…

General Relativity and Quantum Cosmology · Physics 2021-11-17 E. I. Guendelman , E. Zamlung , D. Benisty

The existence of a Noether symmetry for a given minisuperspace cosmological model is a sort of selection rule to recover classical behaviours in cosmic evolution since oscillatory regimes for the wave function of the universe come out. The…

General Relativity and Quantum Cosmology · Physics 2015-06-25 S. Capozziello , G. Lambiase

We study some problems arising from the introduction of a complex scalar field in cosmology, modelling its possible behaviors in both the inflationary and dark energy stages of the universe. Such examples contribute to show that, while the…

High Energy Physics - Theory · Physics 2015-05-19 Giampiero Esposito , Raju Roychowdhury , Claudio Rubano , Paolo Scudellaro

We investigate effects of noncommutativity of phase space generated by two scalar fields conformally coupled to curvature in FRW cosmology. We restrict deformation of minisuperspace to noncommutativity between scalar fields and between…

General Relativity and Quantum Cosmology · Physics 2010-11-30 Behrooz Malekolkalami , Mehrdad Farhoudi

Taking the Noether gauge symmetry approach into account, we find spherically symmetric static black hole solutions of the non-minimal gauge-gravity Lagrangian of the $\mathcal{R}^\beta F^2$ model. At first, we consider a system of…

General Relativity and Quantum Cosmology · Physics 2023-11-13 S. Mahmoudi , S. Hajkhalili , S. H. Hendi

As is well known, symmetry plays an important role in the theoretical physics. In particular, the well-known Noether symmetry is an useful tool to select models motivated at a fundamental level, and find the exact solution to the given…

General Relativity and Quantum Cosmology · Physics 2012-01-10 Hao Wei , Xiao-Jiao Guo , Long-Fei Wang

We study FRW cosmology for scalar tensor theory where two scalar functions nonminimally coupled to the geometry and matter Lagrangian. In a framework to study stability and attractor solutions of the model in the phase space, we…

General Relativity and Quantum Cosmology · Physics 2011-11-22 Hossein Farajollahi , Amin Salehi , Mohammad Nasiri

In this paper, we consider homogeneous cosmological solutions in the context of the Weyl geometrical scalar-tensor theory. Firstly, we exhibit an anisotropic Kasner type solution taking advantage of some similarities between this theory and…

General Relativity and Quantum Cosmology · Physics 2023-07-11 Adriano Barros , Carlos Romero

We review a system of autonomous differential equations developed in our previous work [1] describing a flat cosmology filled with a barotropic fluid and a scalar field with a modified kinetic term of the form L=F(X)-V(phi). We analyze the…

General Relativity and Quantum Cosmology · Physics 2014-04-04 Josue De-Santiago , Jorge L. Cervantes-Cota

In this paper, we present the cosmological scenario obtained from $f(R,T)$ gravity by using an exponential dependence on the trace of the energy-momentum tensor. With a numerical approach applied to the equations of motion, we show several…

General Relativity and Quantum Cosmology · Physics 2019-11-11 G. Ribeiro , R. Sfair , P. H. R. S. Moraes , J. R. L. Santos , A. de Souza Dutra

In this paper we study scalar perturbations of the metric for nonlinear $f(R)$ models. We consider the Universe at the late stage of its evolution and deep inside the cell of uniformity. We investigate the astrophysical approach in the case…

Cosmology and Nongalactic Astrophysics · Physics 2014-09-04 Maxim Eingorn , Jan Novák , Alexander Zhuk