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We study Palatini f(R) cosmology using Noether symmetry approach for the matter dominated universe. In order to construct a point-like Lagrangian in the flat FRW space time, we use the dynamical equivalence between f(R) gravity and…

广义相对论与量子宇宙学 · 物理学 2011-05-19 Mahmood Roshan , Fatimah Shojai

Noether symmetry for higher order gravity theory has been explored, with the introduction of an auxiliary variable which gives the only correct quantum desccription of the theory, as shown in a series of earlier papers. The application of…

天体物理学 · 物理学 2008-11-26 A. K. Sanyal , B. Modak , C. Rubano , E. Piedipalumbo

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…

广义相对论与量子宇宙学 · 物理学 2022-11-14 Francesco Bajardi , Rocco D'Agostino , Micol Benetti , Vittorio De Falco , Salvatore Capozziello

The Noether symmetry of a generic $f(R)$ cosmological model is investigated by utilizing the behavior of the corresponding Lagrangian under the infinitesimal generators of the desired symmetry. We explicitly calculate the form of $f(R)$ for…

广义相对论与量子宇宙学 · 物理学 2008-11-26 Babak Vakili

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…

广义相对论与量子宇宙学 · 物理学 2021-11-29 Francesco Bajardi , Salvatore Capozziello

Extended $f(R)$ theories of gravity have been investigated from the symmetry point of view. We briefly has been investigated Noether symmetry of two types of extended $f(R)$ theories: $f(R,T)$ theory, in which curvature is coupled non…

广义相对论与量子宇宙学 · 物理学 2018-10-09 D. Momeni , R. Myrzakulov , E. Güdekli

In metric formalism, Noether symmetry of F(R) theory of gravity in vacuum and in the presence of pressureless dust yields $F(R)\propto R^\frac{3}{2}$ along with the conserved current $\frac{d}{dt} (a\sqrt R)$ in Robertson-Walker metric and…

广义相对论与量子宇宙学 · 物理学 2017-11-06 Nayem Sk

The exact solutions of spherically symmetric space-times are explored by using Noether symmetries in $f(R,\phi,X)$ gravity with $R$ the scalar curvature, $\phi$ a scalar field and $X$ the kinetic term of $\phi$. Some of these solutions can…

广义相对论与量子宇宙学 · 物理学 2019-02-20 Sebastian Bahamonde , Kazuharu Bamba , Ugur Camci

In this study, we consider a flat Friedmann-Robertson-Walker (FRW) universe in the context of Palatini $f(R)$ theory of gravity. Using the dynamical equivalence between $f(R)$ gravity and scalar-tensor theories, we construct a point…

广义相对论与量子宇宙学 · 物理学 2012-02-02 Y. Kucukakca , U. Camci

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…

广义相对论与量子宇宙学 · 物理学 2018-06-19 H. R. Fazlollahi

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…

宇宙学与河外天体物理 · 物理学 2014-09-26 Kaushik Sarkar , Nayem Sk. , Subhra Debnath , Abhik Kumar Sanyal

Symmetry plays a crucial role in theoretical physics, especially Noether symmetry, which is a powerful approach for identifying the models at the fundamental level. The exact solution is provided within the point-like Lagrangian framework.…

广义相对论与量子宇宙学 · 物理学 2025-10-21 M. Mahmoudzadeh Baghbani , K. Atazadeh , M. Mousavi

Unlike F(R) gravity, pure metric F(T) gravity in the vacuum dominated era, ends up with an imaginary action and is therefore not feasible. This eerie situation may only be circumvented by associating a scalar field, which can also drive…

广义相对论与量子宇宙学 · 物理学 2023-07-26 Manas Chakrabortty , Nayem Sk , Abhik Kumar Sanyal

This paper determines the existence of Noether symmetry in non-minimally coupled $f(R,T)$ gravity admitting minimal coupling with scalar field models. We consider a generalized spacetime which corresponds to different anisotropic and…

广义相对论与量子宇宙学 · 物理学 2017-04-26 M. Sharif , Iqra Nawazish

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…

广义相对论与量子宇宙学 · 物理学 2020-02-21 M. Farasat Shamir

We consider Noether symmetry approach to find out exact cosmological solutions in $f(T)$-gravity. Instead of taking into account phenomenological models, we apply the Noether symmetry to the $f(T)$ gravity. As a result, the presence of such…

综合物理 · 物理学 2012-05-29 K. Atazadeh , F. Darabi

As it is well known, symmetry plays a crucial role in the theoretical physics. On other hand, the Noether symmetry is a useful procedure to select models motivated at a fundamental level, and to discover the exact solution to the given…

综合物理 · 物理学 2018-01-16 Ali Aghamohammadi

We give details and derivations for the Noether invariance theory that characterizes the spatial equilibrium structure of inhomogeneous classical many-body systems, as recently proposed and investigated for bulk systems [F. Samm\"uller…

软凝聚态物质 · 物理学 2024-04-23 Sophie Hermann , Florian Sammüller , Matthias Schmidt

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…

宇宙学与河外天体物理 · 物理学 2015-06-11 Nayem Sk. , Abhik Kumar Sanyal

Under conformal transformation, f(R) theory of gravity in Palatini formalism leads to a Brans-Dicke type of scalar-tensor equivalent theory with a wrong sign in the effective kinetic energy term. This means, the effective scalar acts as the…

广义相对论与量子宇宙学 · 物理学 2020-07-15 Manas Chakrabortty , Nayem Sk , Abhik Kumar Sanyal
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