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Related papers: F(R) cosmology via Noether symmetry and lambda-Cha…

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We investigate the main features of the flat Friedmann-Lema{\i}tre-Robertson-Walker cosmological models in the f(T) teleparallel gravity. In particular, a general approach to find out exact cosmological solutions in f (T) gravity is…

General Relativity and Quantum Cosmology · Physics 2015-06-17 S. Basilakos , S. Capozziello , M. De Laurentis , A. Paliathanasis , M. Tsamparlis

The equation of state of Chaplygin Gas is one of the simplest ways to illustrate dark energy effects during the late time. Indeed, while one uses the equation of state of Chaplygin Gas, the continuity equation gives specific energy density…

General Physics · Physics 2018-07-20 H. R. Fazlollahi

Instead of assuming a form of gravity and demand cosmology fit with $\Lambda CDM$, a potentially `viable' $f(R)$ gravity model is derived assuming an alternative model of cosmology. Taking the `designer' approach to $f(R)$, a new class of…

General Relativity and Quantum Cosmology · Physics 2018-01-16 Rohin Kumar

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

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

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

Noether gauge symmetry for F(R) theory of gravity has been explored recently. The fallacy is that, even after setting gauge to vanish, the form of F(R) \propto R^n (where n \neq 1, is arbitrary) obtained in the process, has been claimed to…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Nayem Sk. , Abhik Kumar Sanyal

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

In this paper, we investigate the newly developed $f(R,\mathbf{T}^2)$ theory ($R$ is the Ricci scalar and $\mathbf{T}^2=T_{\alpha\beta}T^{\alpha\beta},~T _{\alpha\beta}$ demonstrates the energy-momentum tensor) to explore some viable…

General Relativity and Quantum Cosmology · Physics 2021-03-10 M. Sharif , M. Zeeshan Gul

In this paper, a complete classification of Friedmann-Robertson-Walker (FRW) spacetime by using approximate Noether approach is presented. Considered spacetime is discussed for three different types of universe i.e. flat, open and closed.…

General Relativity and Quantum Cosmology · Physics 2015-07-08 Adil Jhangeer , M. Farasat Shamir , Tayyaba Naz , Nazish Iftikhar

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

Noether symmetry of F(R) theory of gravity in vacuum or in matter dominated era yields three-half power law of R. We show that this particular curvature invariant term is very special in the context of isotropic and homogeneous cosmological…

Cosmology and Nongalactic Astrophysics · Physics 2013-02-18 Kaushik Sarkar , Nayem Sk. , Soumendranath Ruz , Subhra Debnath , Abhik Kumar Sanyal

It is well known that the Noether symmetry approach proves to be very useful not only to fix physically viable cosmological models but also to reduce dynamics and achieve exact solutions. In this work, We examine a formal framework of…

General Relativity and Quantum Cosmology · Physics 2018-09-05 Phongpichit Channuie , Davood Momeni

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

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

The paper deals with phantom scalar field cosmology in Einstein gravity. At first using Lie symmetry, the coupling function to the kinetic term and the potential function of the scalar field and the equation of state parameter of the matter…

General Relativity and Quantum Cosmology · Physics 2016-04-27 Sourav Dutta , Subenoy Chakraborty

The present work explores different evolutionary phases of isotropically homogeneous and flat cosmos filled with dust fluid in non-minimally coupled gravity. We consider different models of this gravity to discuss the presence of symmetry…

General Relativity and Quantum Cosmology · Physics 2024-07-04 Iqra Nawazish , M. Sharif

We perform a detailed study of the modified gravity $f(R)$ models in the light of the basic geometrical symmetries, namely Lie and Noether point symmetries, which serve to illustrate the phenomenological viability of the modified gravity…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 A. Paliathanasis , M. Tsamparlis , S. Basilakos

The resolution of the problem of cosmological singularity in the framework of gauge theories of gravitation is discussed. Generalized cosmological Friedmann equations for homogeneous isotropic models filled by interacting scalar fields and…

General Relativity and Quantum Cosmology · Physics 2017-08-23 Albert V. Minkevich

The main objective of this article is to examine some physically viable solutions through the Noether symmetry technique in $f(R, T^{2})$ theory. For this purpose, we assume a generalized anisotropic and homogenous spacetime that yields…

General Relativity and Quantum Cosmology · Physics 2023-06-14 M. Sharif , M. Zeeshan Gul