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Related papers: Palatini f(R) gravity and Noether symmetry

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In this paper, we present a complete Noether Symmetry analysis in the framework of scalar-tensor cosmology. Specifically, we consider a non-minimally coupled scalar field action embedded in the FLRW spacetime and provide a full set of…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-09 A. Paliathanasis , M. Tsamparlis , S. Basilakos , S. Capozziello

This paper is devoted to explore modified $f(\mathcal{R})$ theories of gravity using Noether symmetry approach. For this purpose, Friedmann-Robertson-Walker spacetime is chosen to investigate the cosmic evolution. The study is mainly…

General Relativity and Quantum Cosmology · Physics 2020-02-21 M. Farasat Shamir

We sketch the main features of the Noether Symmetry Approach, a method to reduce and solve dynamics of physical systems by selecting Noether symmetries, which correspond to conserved quantities. Specifically, we take into account the…

General Relativity and Quantum Cosmology · Physics 2023-08-24 Francesco Bajardi , Salvatore Capozziello , Tiziana Di Salvo , Francesca Spinnato

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

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

In the framework of f(R) scalar-tensor cosmology, we use the Noether symmetry approach to find the cosmological models consistent with the Noether symmetry. We obtain the functions f(R) and H(a), or the corresponding differential equations,…

General Relativity and Quantum Cosmology · Physics 2015-05-21 F. Darabi , S. Asgharinya

Discrepancies between observations at early and late cosmic epochs, and the vacuum energy problem associated with the interpretation of cosmological constant, are questioning the $\Lambda$CDM model. Motivated by these conceptual and…

General Relativity and Quantum Cosmology · Physics 2022-11-14 Francesco Bajardi , Rocco D'Agostino , Micol Benetti , Vittorio De Falco , Salvatore Capozziello

The present work deals with scalar field cosmology in the framework of a quantum gravity modified Einstein-Hilbert Lagrangian with variable $G$ and $\Lambda$. Using Renormalization group, variable $G$ behaves as a minimally coupled filed…

General Relativity and Quantum Cosmology · Physics 2019-11-22 Santu Mondal , Sourav Dutta , Subenoy Chakraborty

Nowadays, $f(R)$ theory has been one of the leading modified gravity theories to explain the current accelerated expansion of the universe, without invoking dark energy. It is of interest to find the exact cosmological solutions of $f(R)$…

General Relativity and Quantum Cosmology · Physics 2015-12-25 Hao Wei , Hong-Yu Li , Xiao-Bo Zou

Classical equivalence between Jordan's and Einstein's frame counterparts of F(R) theory of gravity has recently been questioned, since the two produce different Noether symmetries, which couldn't be translated back and forth using…

General Relativity and Quantum Cosmology · Physics 2018-06-27 Nayem Sk. , Abhik Kumar Sanyal

We study the evolution of a two dimensional minisuperspace cosmological model in classical and quantum levels by the Noether symmetry approach. The phase space variables turn out to correspond to the scale factor of a…

General Relativity and Quantum Cosmology · Physics 2012-01-23 Babak Vakili , Farhad Khazaie

The present work deals with Einstein-aether Scalar tensor gravity in the background of homogeneous and isotropic flat FLRW space-time model. The Noether symmetry vector identifies a transformation in the augmented space so that the field…

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

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

We consider modified teleparallel gravity, (f(T) gravity), as a framework to explain the present accelerated expansion of the universe. The matter component is assumed to be cold dark matter. To find the explicit form of the function $f$,…

General Relativity and Quantum Cosmology · Physics 2015-06-11 H. Mohseni Sadjadi

Noether symmetries from geodetic Lagrangian for time-conformal plane symmetric spacetime are presented. Here, time conformal factor is used to find the approximate Noether symmetries. This is a generalization of the idea discussed by I.…

General Relativity and Quantum Cosmology · Physics 2015-11-04 Farhad Ali , Tooba Feroze

Canonization of F(R) theory of gravity to explore Noether symmetry is performed treating R - 6(\frac{\ddot a}{a} + \frac{\dot a^2}{a^2} + \frac{k}{a^2}) = 0 as a constraint of the theory in Robertson-Walker space-time, which implies that R…

Cosmology and Nongalactic Astrophysics · Physics 2014-09-26 Kaushik Sarkar , Nayem Sk. , Subhra Debnath , Abhik Kumar Sanyal

The form of the coupling of the scalar field with gravity and the potential have been found by applying Noether theorem to two dimensional minisuperspaces in induced gravity model. It has been observed that though the forms thus obtained…

General Relativity and Quantum Cosmology · Physics 2008-11-26 A. K. Sanyal , B. Modak

We investigate the viability of f(R) theories in the framework of the Palatini approach as solutions to the problem of the observed accelerated expansion of the universe. Two physically motivated popular choices for f(R) are considered:…

Astrophysics · Physics 2009-11-10 S. Capozziello , V. F. Cardone , M. Francaviglia

Motivated by the properties of matter quantum fields in curved space-times, we work out a gravity theory that combines the Born-Infeld gravity Lagrangian with an $f(R)$ piece. To avoid ghost-like instabilities, the theory is formulated…

High Energy Physics - Theory · Physics 2014-09-18 Andrey N. Makarenko , Sergei Odintsov , Gonzalo J. Olmo

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