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相关论文: Proper time reparametrization in cosmology: Mobius…

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We show that the simplest FLRW cosmological system consisting in the homogeneous and isotropic massless Einstein-Scalar system enjoys a hidden conformal symmetry under the 1D conformal group $SL(2,\mathbb{R})$ acting as Mobius…

广义相对论与量子宇宙学 · 物理学 2025-02-06 Jibril Ben Achour , Etera R. Livine

It was recently shown that the homogeneous and isotropic cosmology of a massless scalar field coupled to general relativity exhibits a new hidden conformal invariance under Mobius transformation of the proper time, additionally to the…

广义相对论与量子宇宙学 · 物理学 2020-02-28 Jibril Ben Achour , Etera R. Livine

The homogeneous Friedman-Lema\^\i tre-Robertson-Walker (FLRW) cosmology of a free scalar field with vanishing cosmological constant was recently shown to be invariant under the one-dimensional conformal group $\textrm{SL}(2,\mathbb{R})$…

广义相对论与量子宇宙学 · 物理学 2020-09-17 Jibril Ben Achour , Etera R. Livine

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 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…

广义相对论与量子宇宙学 · 物理学 2023-12-19 Nikolaos Dimakis , Kevin Duffy , Alex Giacomini , Alexander Yu. Kamenshchik , Genly Leon , Andronikos Paliathanasis

The construction of physical models with local time-reparametrization invariance is reviewed. Negative-energy contributions to the hamiltonian are shown to be crucial for the realization of this reparametrization symmetry. The covariant…

高能物理 - 理论 · 物理学 2015-11-24 Jan-Willem van Holten , Richard Kerner

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…

广义相对论与量子宇宙学 · 物理学 2021-03-10 M. Sharif , M. Zeeshan Gul

The aim of the present work is to investigate a non-minimally coupled scalar field model through the Noether symmetry approach, with the radiation, matter and cosmological constant eras being analyzed. The Noether symmetry condition allows…

广义相对论与量子宇宙学 · 物理学 2013-10-15 Rudinei C. de Souza , Gilberto M. Kremer

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…

广义相对论与量子宇宙学 · 物理学 2024-07-12 Dipanakr Laya , Roshni Bhaumik , Sourav Dutta , Subenoy Chakraborty

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…

广义相对论与量子宇宙学 · 物理学 2015-06-17 S. Basilakos , S. Capozziello , M. De Laurentis , A. Paliathanasis , M. Tsamparlis

We consider the symmetric teleparallel $f\left( Q\right) $-gravity in Friedmann--Lema\^{\i}tre--Robertson--Walker cosmology with nonzero spatial curvature. For a nonlinear $f\left( Q\right) $ model there exist always the limit of General\…

广义相对论与量子宇宙学 · 物理学 2023-10-09 Andronikos Paliathanasis

We consider the existence of a Noether symmetry in the scalar-tensor theory of gravity in flat Friedman Robertson Walker (FRW) cosmology. The forms of coupling function $\omega(\phi)$ and generic potential $V(\phi)$ are obtained by…

高能物理 - 理论 · 物理学 2007-05-23 Hossein Motavali , Mahdi Golshani

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

A detailed study of the modified gravity, f(R) models is performed, using that the Noether point symmetries of these models are geometric symmetries of the mini superspace of the theory. It is shown that the requirement that the field…

广义相对论与量子宇宙学 · 物理学 2015-01-05 Andronikos Paliathanasis

We explore Noether gauge symmetries of FRW and Bianchi I universe models for perfect fluid in scalar-tensor gravity with extra term $R^{-1}$ as curvature correction. Noether symmetry approach can be used to fix the form of coupling function…

广义相对论与量子宇宙学 · 物理学 2014-03-04 M. Sharif , Saira Waheed

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 $f(R)$…

广义相对论与量子宇宙学 · 物理学 2015-12-25 Hao Wei , Hong-Yu Li , Xiao-Bo Zou

In the context of the Relativistic Quantum Geometry formalism, where the cosmological constant is promoted to a dynamical variable by attributing it a geometric interpretation as a result of a flux on the boundary of a manifold and…

广义相对论与量子宇宙学 · 物理学 2025-04-15 Juan Ignacio Musmarra , Claudia Moreno , Rafael Hernández-Jiménez

This paper is devoted to investigate $f(R)$ gravity using Noether symmetry approach. For this purpose, we consider Friedmann Robertson-Walker (FRW) universe and spherically symmetric spacetimes. The Noether symmetry generators are evaluated…

广义相对论与量子宇宙学 · 物理学 2012-08-03 M. Farasat Shamir , Adil Jhangeer , Akhlaq Ahmad Bhatti

We apply the Noether symmetries to constrain the unknown functions of chameleon gravity in the cosmological scenario of a spatially flat Friedmann--Lema\^{\i}tre--Robertson--Walker space-time with an ideal gas. For this gravitational model…

广义相对论与量子宇宙学 · 物理学 2023-06-22 Andronikos Paliathanasis

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
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