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相关论文: A reconstruction method for anisotropic universes …

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We extend the idea of unimodular gravity to the modified $f(R,T)$ theories. A new class of cosmological solutions, that the unimodular constraint on the metric imposes on the $f(R,T)$ theories, are studied. This extension is done in both…

广义相对论与量子宇宙学 · 物理学 2017-11-22 F. Rajabi , K. Nozari

We present the reconstruction method of $f(R)$ gravity for the homogeneous and anisotropic Bianchi-I spacetime, which was previously formulated only for homogeneous and isotropic FLRW spacetime. We argue in this paper that for anisotropic…

广义相对论与量子宇宙学 · 物理学 2018-07-11 Saikat Chakraborty

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

The so-called unimodular version of General Relativity is revisited. Unimodular gravity is constructed by fixing the determinant of the metric, what leads to the trace-free part of the equations instead of the usual Einstein field…

广义相对论与量子宇宙学 · 物理学 2016-06-22 Diego Saez-Gomez

We study mimetic $F(R)$ gravity with potential and Lagrange multiplier constraint. In the context of these theories, we introduce a reconstruction technique which enables us to realize arbitrary cosmologies, given the Hubble rate and an…

广义相对论与量子宇宙学 · 物理学 2016-02-17 S. D. Odintsov , V. K. Oikonomou

A new strategy for the reconstruction of $f(R)$ gravity models have been attempted using Raychaudhuri equation. Two examples, one for an eternally accelerating universe and the other for one that mimics a ${\Lambda}$CDM expansion history…

广义相对论与量子宇宙学 · 物理学 2019-04-09 Shibendu Gupta Choudhury , Ananda Dasgupta , Narayan Banerjee

The new model of modified $F(R)$ gravity theory with the function $F(R) = R+(a/\gamma) \arcsin(\gamma R)$ is suggested and investigated. Constant curvature solutions corresponding to the extremum of the effective potential are obtained. We…

综合物理 · 物理学 2015-07-20 S. I. Kruglov

In this work we introduce and study the unimodular-mimetic $f(\mathcal{G})$ gravity, where unimodular and mimetic constraints are incorporated through corresponding Lagrange multipliers. We present field equations governing this theory and…

广义相对论与量子宇宙学 · 物理学 2023-11-13 Adam Z. Kaczmarek , Dominik Szczęśniak

We present a reconstruction technique for models of $f(R)$ gravity from the Chaplygin scalar field in flat de Sitter spacetimes. Exploiting the equivalence between $f(R)$ gravity and scalar-tensor theories, and treating the Chaplygin gas as…

广义相对论与量子宇宙学 · 物理学 2018-02-14 Heba Sami , Neo Namane , Joseph Ntahompagaze , Maye Elmardi , Amare Abebe

We propose a new model of modified $F(R)$ gravity theory with the function $F(R) = (1/\beta) \arcsin(\beta R)$. Constant curvature solutions corresponding to the flat and de Sitter spacetime are obtained. The Jordan and Einstein frames are…

综合物理 · 物理学 2015-07-24 S. I. Kruglov

We investigate the cosmological reconstruction in modified f(R,T) gravity, where R is the Ricci scalar and T the trace of the stress-energy tensor. Special attention is attached to the case in which the function f is given by f (R, T) = f1…

宇宙学与河外天体物理 · 物理学 2015-05-28 M. J. S. Houndjo

In this paper we study a modified version of unimodular general relativity in the context of $f(G)$, $G$ denoting the Gauss-Bonnet invariant. We attach attention to Bianchi-type I and Friendmann-Robertson-Walker universes and search for…

广义相对论与量子宇宙学 · 物理学 2017-10-25 M. J. S. Houndjo

Recently, a new strategy to the reconstruction of $f(R)$-gravity models based on the Raychaudhuri equation has been suggested by Choudhury et al. In this paper, utilizing this method, the reconstruction of anisotropic Einstein-Maxwell…

广义相对论与量子宇宙学 · 物理学 2020-06-24 Behzad Tajahmad

We develop the reconstruction program for the number of modified gravities: scalar-tensor theory, $f(R)$, $F(G)$ and string-inspired, scalar-Gauss-Bonnet gravity. The known (classical) universe expansion history is used for the explicit and…

高能物理 - 理论 · 物理学 2010-04-06 Shin'ichi Nojiri , Sergei D. Odintsov

In this work, we investigate the cosmological dynamics of an anisotropic Universe within the framework of $f(R,T)$ gravity by incorporating pressureless dark matter and the dark energy models. The analysis is carried out in a Bianchi type-I…

广义相对论与量子宇宙学 · 物理学 2026-05-13 S. H. Shekh , N. Myrzakulov , Anirudh Pradhan , M. Zeyauddin

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

Accelerating cosmological models are constructed in a modified gravity theory dubbed as $f(R,T)$ gravity at the backdrop of an anisotropic Bianchi type-III universe. $f(R,T)$ is a function of the Ricci scalar $R$ and the trace $T$ of the…

广义相对论与量子宇宙学 · 物理学 2017-06-21 S K Sahu , S K Tripathy , P K Sahoo , A Nath

In the previous article Eur. Phys. J. Plus 136, 590 (2021) (arXiv: 2110.15396) we have proposed a reconstruction method for the kinetic gravity braiding theory in the framework of the flat Friedman-Robertson-Walker spacetime. Here we…

广义相对论与量子宇宙学 · 物理学 2022-07-05 Ruslan K. Muharlyamov , Tatiana N. Pankratyeva

Anisotropic cosmological models are constructed in $f(R,T)$ gravity theory to investigate the dynamics of universe concerning the late time cosmic acceleration. Using a more general and simple approach, the effect of the coupling constant…

综合物理 · 物理学 2018-10-05 B. Mishra , Sankarsan Tarai , S. K. Tripathy

We reconstruct the geometrical $f(T)$ actions in the framework of unimodular $f(T)$ gravity. The unimodular $f(T)$ gravity yields stunning properties related to the generalized Friedmann equations. Indeed, it has been found that depending…

广义相对论与量子宇宙学 · 物理学 2017-01-03 S. B. Nassur , C. Ainamon , M. J. S. Houndjo , J. Tossa
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