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相关论文: A new approach to reconstruction methods in $f(R)$…

200 篇论文

In this manuscript, we present a number of fascinating explicit reconstructions for the $f(Q)$ gravity from the background of Friedmann-La\^imatre-Robertson-Walker (FLRW) evolution history. We find the more general functions of…

广义相对论与量子宇宙学 · 物理学 2022-10-25 Gaurav N. Gadbail , Sanjay Mandal , P. K. Sahoo

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

We develop the general scheme for modified $f(R)$ gravity reconstruction from any realistic FRW cosmology. We formulate several versions of modified gravity compatible with Solar System tests where the following sequence of cosmological…

高能物理 - 理论 · 物理学 2008-11-26 Shin'ichi Nojiri , Sergei D. Odintsov

We consider the Chiral Cosmological Models (CCMs) and modified gravity theories associated with them. Generalization of the superpotential method for a general CCM with several scalar fields is performed, and the method of construction CCMs…

广义相对论与量子宇宙学 · 物理学 2019-09-25 S. V. Chervon , I. V. Fomin , E. O. Pozdeeva , M. Sami , S. Yu. Vernov

We discuss the cosmological reconstruction of $f(R,R_{\alpha\beta}R^{\alpha\beta},\phi)$ (where $R$, $R_{\alpha\beta}R^{\alpha\beta}$ and $\phi$ represents the Ricci scalar, Ricci invariant and scalar field) corresponding to power law and…

广义相对论与量子宇宙学 · 物理学 2017-05-01 M. Zubair , Farzana Kousar

We reconstruct the viable f(G) gravity models from the observations and provide the analytic solutions that well describe our numerical results. In order to avoid unphysical challenges that occur during the numerical reconstruction, we…

宇宙学与河外天体物理 · 物理学 2020-06-17 Seokcheon Lee , Gansukh Tumurtushaa

One of the most favourable extensions of General Relativity is the $f(R)$ gravity. $f(R)$ gravity in Palatini formalism can be a realistic alternative to the dark energy problem. In this work we study a recently introduced dark energy…

广义相对论与量子宇宙学 · 物理学 2022-05-20 Dhruba Jyoti Gogoi , Umananda Dev Goswami

The basic aim of this manuscript is to investigate the cosmological solutions in the context of the modified $f(R, T)$ theory of gravity, where $R$ is the Ricci scalar and $T$ is the trace of the energy-momentum tensor. For our current…

广义相对论与量子宇宙学 · 物理学 2024-03-26 Adnan Malik , Tayyaba Naz , Aimen Rauf , M. Farasat Shamir , Z. Yousaf

We present the data-driven reconstruction of gravitational theories and Dark Energy models on cosmological scales. We showcase the power of present cosmological probes at constraining these models and quantify the knowledge of their…

宇宙学与河外天体物理 · 物理学 2020-04-22 Marco Raveri

We consider a model for gravity that is invariant under global scale transformations. It includes one extra real scalar field coupled non-minimally to the gravity fields. In this model all the dimensionful parameters like the gravitational…

广义相对论与量子宇宙学 · 物理学 2012-02-06 Pankaj Jain , Purnendu Karmakar , Subhadip Mitra , Sukanta Panda , Naveen K. Singh

Recently, the research community has been exploring fractional calculus to address problems related to cosmology; in this approach, the gravitational action integral is altered, leading to a modified Friedmann equation, then the resulting…

广义相对论与量子宇宙学 · 物理学 2023-02-07 Bayron Micolta-Riascos , Alfredo D. Millano , Genly Leon , Cristián Erices , Andronikos Paliathanasis

We propose a new framework for studying the cosmology of $f(R)$ gravity which completely avoids using the reconstruction programme. This allows us to easily obtain a qualitative feel of how much the $\Lambda$CDM model differs from other…

广义相对论与量子宇宙学 · 物理学 2021-06-22 Saikat Chakraborty , Kelly MacDevette , Peter Dunsby

Cosmography and galaxy clusters are discussed in the framework of f(R)-gravity giving a comprehensive review of recent results.

宇宙学与河外天体物理 · 物理学 2015-05-13 S. Capozziello , V. Salzano

In this paper, we have presented the cosmological model of the Universe that represents late time cosmic acceleration in torsion based gravitational theory, the $f(T)$ gravity. A well motivated parametrization for the Hubble parameter has…

广义相对论与量子宇宙学 · 物理学 2025-11-04 Suraj Kumar Behera , Pratik P. Ray , B. Mishra

Cosmography can be considered as a sort of a model-independent approach to tackle the dark energy/modified gravity problem. In this review, the success and the shortcomings of the $\Lambda$CDM model, based on General Relativity and standard…

广义相对论与量子宇宙学 · 物理学 2019-04-09 Salvatore Capozziello , Rocco D'Agostino , Orlando Luongo

We consider cosmological models based on the scalar-torsion gravity implying non-minimal coupling between torsion and the scalar field with certain relations between model's parameters. Based on observational constraints on the values of…

广义相对论与量子宇宙学 · 物理学 2024-11-14 I. V. Fomin , S. V. Chervon , E. S. Dentsel

In this work we present cosmological solutions from the simplest non-trivial $T$-dependence in $f(R,T)$ theory of gravity, with $R$ and $T$ standing for the Ricci scalar and trace of the energy-momentum tensor, respectively. Although such…

高能物理 - 理论 · 物理学 2016-06-29 P. H. R. S. Moraes , G. Ribeiro , R. A. C. Correa

Recently, a new kind of $f(z)$ theory is proposed to provide a different perspective for the development of reliable alternative models of gravity in which the $f(R)$ Lagrangian terms are reformulated as polynomial parameterizations $f(z)$.…

宇宙学与河外天体物理 · 物理学 2020-07-15 Ji-Yao Wang , Chao-Jun Feng , Xiang-Hua Zhai , Xin-Zhou Li

We construct the $F(R)$ gravity models with exact particular solutions using the conformal transformation and the superpotential method for the corresponding models in the Einstein frame. The functions $F(R)$ are obtained explicitly. We…

广义相对论与量子宇宙学 · 物理学 2020-10-06 S. Yu. Vernov , V. R. Ivanov , E. O. Pozdeeva

We have investigated some bouncing cosmological models in an isotropic and homogeneous space time with the F(R) theory of gravity. Two functional forms of F(R) have been investigated with a bouncing scale factor. The dynamical parameters…

广义相对论与量子宇宙学 · 物理学 2024-03-21 A. S. Agrawal , S. Mishra , S. K. Tripathy , B. Mishra