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相关论文: Reconstruction of Einstein-Aether Gravity from oth…

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Here we briefly discuss the Einstein-Aether gravity theory by modification of Einstein-Hilbert action. We find the modified Friedmann equations and then from the equations we find the effective density and pressure for Einstein-Aether…

广义相对论与量子宇宙学 · 物理学 2013-11-05 Ujjal Debnath

In this paper, we reconstruct various solutions for the accelerated universe in the Einstein-Aether theory of gravity. For this purpose, we obtain the effective density and pressure for Einstein-Aether theory. We reconstruct the…

综合物理 · 物理学 2019-07-23 Shamaila Rani , Abdul Jawad , Kazuharu Bamba , Irfan Ullah Malik

We establish a well-posedness theory for the f(R) theory of modified gravity, which is a generalization of Einstein's theory of gravitation. The scalar curvature R of the spacetime, which arises in the integrand of the Einstein-Hilbert…

偏微分方程分析 · 数学 2014-12-30 Philippe G. LeFloch , Yue Ma

A modified theory of gravity with the function $F(R) = R\exp(\alpha R)$ instead of Ricci scalar $R$ in the Einstein$-$Hilbert action is considered and analyzed. The action of the model is converted into Einstein$-$Hilbert action at small…

广义相对论与量子宇宙学 · 物理学 2013-09-30 S. I. Kruglov

We present a comprehensive investigation exploring the theoretical framework of Einstein-Aether gravity theory when combined with two modified cosmological paradigms: the Barrow Agegraphic Dark Energy (BADE) and its newer variant, the New…

广义相对论与量子宇宙学 · 物理学 2025-06-13 Banadipa Chakraborty , Tamal Mukhopadhyay , Anamika Kotal , Ujjal Debnath

In this paper, we will analyse the cosmological models in Einstein-aether gravity, which is a modified theory of gravity in which a time-like vector field breaks the Lorentz symmetry. We will use this formalism to analyse different…

广义相对论与量子宇宙学 · 物理学 2017-04-19 Antonio Pasqua , Surajit Chattopadhyay , Davood Momeni , Muhammad Raza , Ratbay Myrzakulov , Mir Faizal

A reconstruction of modified gravity is proposed by establishing a correspondence between the effective density of the modified gravity and the holographic density. The non-homogeneous term in the modified Friedmann equation, generated by…

广义相对论与量子宇宙学 · 物理学 2019-02-20 L. N. Granda

We propose a modified gravity theory by extending the Einstein-Hilbert action with an arbitrary function of the Ricci scalar and the Kretschmann scalar invariants. The resulting modified Friedmann equations for a spatially flat FRW universe…

广义相对论与量子宇宙学 · 物理学 2026-05-29 A. Dehyadegari , A. Sheykhi

Einstein-aether theory is extended by allowing for spinning degrees of freedom of the aether. In addition to the acceleration, shear, expansion, and vorticity of the aether velocity field, a spin rotation describing the dynamics of a…

广义相对论与量子宇宙学 · 物理学 2021-09-09 Christopher Kohler

We extend the formalism of the Einstein-Hilbert unimodular gravity in the context of modified $F(R)$ gravity. After appropriately modifying the Friedmann-Robertson-Walker metric in a way that it becomes compatible to the unimodular…

广义相对论与量子宇宙学 · 物理学 2016-06-01 S. Nojiri , S. D. Odintsov , V. K. Oikonomou

An holographic f(R) gravity model of dark energy is proposed. The correspondence between the f(R) geometrical effective energy density with the holographic density, allows the reconstruction of the f(R) gravity in flat FRW background in the…

高能物理 - 理论 · 物理学 2008-12-10 L. N. Granda

In this work, two originally separate adjustments for the Friedmann equations are concurrently considered. Firstly, the fractal structure of the black hole horizon region is imposed by the Barrow entropy. The second adjustment is the…

广义相对论与量子宇宙学 · 物理学 2024-06-13 Tuhina Ghorui , Prabir Rudra , Farook Rahaman

Motivated by Horava-Lifshitz gravity theory, we propose and investigate two kinds of modified gravity theories, the f(R) kind and the K-essence kind, in the Arnowitt-Deser-Misner (ADM) formalism. The f(R) kind includes one ultraviolet (UV)…

宇宙学与河外天体物理 · 物理学 2010-04-07 Changjun Gao

Inspired by the Wald-Kodama entropy $S=A/(4G_{\text{eff}})$ where $A$ is the horizon area and $G_{\text{eff}}$ is the effective gravitational coupling strength in modified gravity with field equation $R_{\mu\nu}-Rg_{\mu\nu}/2=$ $8\pi…

广义相对论与量子宇宙学 · 物理学 2015-07-14 David Wenjie Tian , Ivan Booth

The starting point of this work is the original Einstein action, sometimes called the Gamma squared action. Continuing from our previous results, we study various modified theories of gravity following the Palatini approach. The metric and…

广义相对论与量子宇宙学 · 物理学 2023-09-29 Christian G. Boehmer , Erik Jensko

We formulate the nonminimal aether-modified gravity whose action represents itself as a sum of the usual Einstein-Hilbert action and the CPT-even Lorentz-breaking aether-like gravity term proposed by Carroll. For this theory, we show that…

广义相对论与量子宇宙学 · 物理学 2013-03-27 C. Furtado , J. R. Nascimento , A. Yu. Petrov , A. F. Santos

We present a brief overview of the stability analysis of the Einstein static universe in various modified theories of gravity, like f(R) gravity, Gauss-Bonnet or f(G) gravity, and Horava-Lifshitz gravity.

广义相对论与量子宇宙学 · 物理学 2016-11-15 Christian G. Boehmer , Lukas Hollenstein , Francisco S. N. Lobo , Sanjeev S. Seahra

We review how we can construct the gravity models which reproduces the arbitrary development of the universe. We consider the reconstruction in the Einstein gravity coupled with generalized perfect fluid, scalar-Einstein gravity,…

高能物理 - 理论 · 物理学 2010-04-28 Shin'ichi Nojiri

The Einstein-Aether theory is an alternative theory of gravity in which the spacetime metric is supplemented by a long-range timelike vector field (the "aether" field). Here, for the first time, we apply the full formalism of…

广义相对论与量子宇宙学 · 物理学 2023-12-13 Fatemeh Taherasghari , Clifford M. Will

We investigate the evolution of cosmological perturbations in models of dark energy described by a time-like unit normalized vector field specified by a general function $\mathcal{F}(\mathcal{K})$, so-called Generalized Einstein-Aether…

宇宙学与河外天体物理 · 物理学 2017-10-04 Richard A. Battye , Francesco Pace , Damien Trinh
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