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Related papers: $f(\mathcal{R},\varphi,\chi)$ Cosmology with Noeth…

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We study cosmologies in modified theories of gravity considering Lagrangian density $f(R)$ which is a polynomial function of scalar curvature ($R$) in the Einstein-Hilbert action in vacuum. The field equation obtained from the modified…

Cosmology and Nongalactic Astrophysics · Physics 2009-10-29 B. C. Paul , P. S. Debnath , S. Ghose

We investigate the impact of conformal transformations on the physical properties of solution trajectories in nonmetricity gravity. Specifically, we explore the phase-space and reconstruct the cosmological history of a spatially flat…

General Relativity and Quantum Cosmology · Physics 2023-12-19 Nikolaos Dimakis , Kevin Duffy , Alex Giacomini , Alexander Yu. Kamenshchik , Genly Leon , Andronikos Paliathanasis

Recently, corrections of the $L(R)$ type to Einstein-Hilbert action that become important at small curvature are proposed. Those type of models intend to explain the observed cosmic acceleration without dark energy. We derive the full…

Astrophysics · Physics 2009-11-10 Xinhe Meng , Peng Wang

The cosmological phenomenology of gravity is typically studied in two limits: relativistic perturbation theory (on large scales) and Newtonian gravity (required for smaller, non-linear, scales). Traditional approaches to model-independent…

General Relativity and Quantum Cosmology · Physics 2020-07-21 Daniel B Thomas

We find exact cosmological solutions when the Newton parameter and the cosmological term are dynamically evolving in a renormalization-group improved Hamiltonian approach. In our derivation we use the Noether symmetry approach, leading to…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Alfio Bonanno , Giampiero Esposito , Claudio Rubano , Paolo Scudellaro

The present work deals with a multi-field cosmological model in a spatially flat FLRW space-time geometry. The usual Brans-Dicke(BD) field and another scalar field are minimally coupled to gravity while they interact with each other through…

General Relativity and Quantum Cosmology · Physics 2024-07-10 Dipankar Laya , Sourav Dutta , Subenoy Chakraborty

In this work, we consider F(R) alternative theories of gravity with an eye to Noether symmetry through the gauge theorem. For non-vacuum models, one finds {\Lambda} like gravity with energy density of Chaplygin Gas. We also obtain the…

General Relativity and Quantum Cosmology · Physics 2018-06-19 H. R. Fazlollahi

Spherically symmetric solutions for f(T) gravity models are derived by the so called Noether Symmetry Approach. First, we present a full set of Noether symmetries for some minisuperspace models. Then, we compute analytical solutions and…

General Relativity and Quantum Cosmology · Physics 2014-05-28 A. Paliathanasis , S. Basilakos , E. N. Saridakis , S. Capozziello , K. Atazadeh , F. Darabi , M. Tsamparlis

The theoretical and observational consequences of thermodynamics of open systems, which allow particle creation are investigated in modified $f(R,T)$ ($R$ is the Ricci scalar and $T$ is the trace of energy-momentum tensor) theory of gravity…

General Relativity and Quantum Cosmology · Physics 2014-08-26 C. P. Singh , Vijay Singh

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

We discuss the f(R) gravity model in which the origin of dark energy is identified as a modification of gravity. The Noether symmetry with gauge term is investigated for the f(R) cosmological model. By utilization of the Noether Gauge…

General Physics · Physics 2012-01-16 Ibrar Hussain , Mubasher Jamil , F. M. Mahomed

A generalized teleparallel cosmological model, $f(T_\mathcal{G},T)$, containing the torsion scalar $T$ and the teleparallel counterpart of the Gauss-Bonnet topological invariant $T_{\mathcal{G}}$, is studied in the framework of the Noether…

General Relativity and Quantum Cosmology · Physics 2016-12-21 Salvatore Capozziello , Mariafelicia De Laurentis , Konstantinos F. Dialektopoulos

The solutions for the field equations of $f(R)$ gravity are investigated in static cylindrically symmetric space-time. Conserved quantities of the system, as well as unknown functions, can be determined with the help of the Noether symmetry…

General Relativity and Quantum Cosmology · Physics 2021-09-21 Işıl Başaran Öz , Kazuharu Bamba

Recently, some authors have made a falsifiable claim that Noether gauge symmetry for F(R) theory of gravity coupled to a tachyon field enforces gauge to vanish and leads to F(R) \propto R^2, with a tachyon potential V(\phi) \propto…

Cosmology and Nongalactic Astrophysics · Physics 2013-11-13 Nayem Sk. , Abhik Kumar Sanyal

In this paper, we analyze the modified $f(\mathcal{R})$ gravity models in Friedmann--Lema\^{\i}tre--Robertson--Walker (FLRW) background. The actions of bouncing cosmology are studied under consideration of different viable models in…

General Relativity and Quantum Cosmology · Physics 2021-02-18 M. Ilyas , W. U. Rahman

We look for exact solutions in scalar field cosmology. To achieve this we use $f(R)$ modified gravity with a scalar field and do not specify the the form of the $f(R)$ function. In particular, we study Friedmann universe assuming that…

General Relativity and Quantum Cosmology · Physics 2017-09-14 S. D. Maharaj , R. Goswami , S. V. Chervon , A. V. Nikolaev

Three theoretically plausible techniques to developing a fractional scalar field cosmological model are pointed in this paper; the time-dependent kernel weighted action being then selected. Upon this choice, we proceed to establish (i) a…

General Relativity and Quantum Cosmology · Physics 2026-05-26 S. M. M. Rasouli , J. Marto , D. Oliveira , P. Moniz

We study the evolution of the physical variables in $f\left( Q\right) $-gravity for two families of symmetric and flat connections in a spatially flat Friedmann--Lema\^{\i}tre--Robertson--Walker geometry where the equation of motion for the…

General Relativity and Quantum Cosmology · Physics 2023-05-16 Andronikos Paliathanasis

This paper explores exact cosmological solutions of anisotropic universe model through Noether symmetry technique in energy-momentum squared gravity. This theory resolves the primordial singularity and provides viable cosmological…

General Relativity and Quantum Cosmology · Physics 2023-05-24 M. Sharif , M. Zeeshan Gul

We search for spherically symmetric solutions of f(R) theories of gravity via the Noether Symmetry Approach. A general formalism in the metric framework is developed considering a point-like f(R)-Lagrangian where spherical symmetry is…

General Relativity and Quantum Cosmology · Physics 2008-11-26 S. Capozziello , A. Stabile , A. Troisi
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