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相关论文: Revisiting $f(R,T)$ cosmologies

200 篇论文

In order to constrain $f(R,L_{m})$ gravity from theoretical aspects, its energy conditions are derived in this paper. These energy conditions given by us are quite general and can be degenerated to the well-known energy conditions in…

综合物理 · 物理学 2015-06-12 Jun Wang , Kai Liao

In this paper, we have investigated some exact cosmological models in Myrzakulov gravity using a flat Friedmann-Lematre-Robertson-Walker (FLRW) spacetime metric. We have considered the modified Lagrangian function as $F(R,T)=R+\lambda T$,…

广义相对论与量子宇宙学 · 物理学 2024-08-14 Dinesh Chandra Maurya , Ratbay Myrzakulov

The theoretical and observational consequences of thermodynamics of open systems, which allow particle creation are investigated in modified $f(R,T)$ ($R$ is the Ricci scalar and $T$ is the trace of energy-momentum tensor) theory of gravity…

广义相对论与量子宇宙学 · 物理学 2014-08-26 C. P. Singh , Vijay Singh

Motivated by earlier works on reconstruction of modified gravity models with dark energy components, we extend them by considering a newly proposed model of (m, n)- type of holographic dark energy for two models of modified gravity, f(R)…

宇宙学与河外天体物理 · 物理学 2013-08-14 M. Umar Farooq , Mubasher Jamil , Davood Momeni , Ratbay Myrzakulov

Modified gravity is one of the most favorable candidates for explaining the current accelerating expansion of the Universe. In this regard, we study the viability of an alternative gravitational theory, namely $f(R,G)$, by imposing energy…

广义相对论与量子宇宙学 · 物理学 2014-01-30 K. Atazadeh , F. Darabi

In recent years, modifications to General Relativity (GR) have been explored to address cosmological observations, particularly in the context of late-time cosmic acceleration. Among these, modifications based on the Teleparallel Equivalent…

宇宙学与河外天体物理 · 物理学 2025-08-29 Saurabh Verma , Archana Dixit , Anirudh Pradhan , M. S. Barak

The present paper is devoted to the study of bouncing cosmology in $f(R,T)$ modified gravity where we presume $f(R,T) = R + 2 \lambda T$, with $R$ the Ricci scalar, $T$ the trace of energy momentum tensor and $\lambda$ the model parameter.…

广义相对论与量子宇宙学 · 物理学 2020-04-07 Snehasish Bhattacharjee , P. K. Sahoo

This study proposes a unified framework comprising two complementary approaches to constrain three functional forms of $f(T,B)$ gravity, namely the linear, quadratic, and general power law models, by jointly utilizing early and late…

宇宙学与河外天体物理 · 物理学 2026-01-07 Yahia Al-Omar , Majida Nahili , Nidal Chamoun , Marwan Al-Raeei

A cubic correction of $f(T)$ gravity, where $T$ is the teleparallel scalar torsion, is considered to describe gravity in spatially flat Friedmann-Robertson-Walker model. A scale factor permitting departure from inflation era has been…

综合物理 · 物理学 2015-11-06 G. G. L. Nashed , W. El Hanafy

The present research paper is an investigation of dark energy nature of logarithmic $f(R, T)$-gravity cosmology in a flat FLRW space-time universe. We have derived modified Einstein's field equations for the function $f(R, T)=R-16\pi…

广义相对论与量子宇宙学 · 物理学 2023-06-06 Dinesh Chandra Maurya , Jagat Singh , Lalit Kumar Gaur

The present paper examines the validity of energy bounds in a modified theory of gravity involving non-minimal coupling of torsion scalar and perfect fluid matter. In this respect, we formulate the general inequalities of energy conditions…

广义相对论与量子宇宙学 · 物理学 2015-02-11 M. Zubair , Saira Waheed

In the context of the late time cosmic acceleration phenomenon, many geometrically modified theories of gravity have been proposed in recent times. In this paper, we have investigated the role of a recently proposed extension of symmetric…

广义相对论与量子宇宙学 · 物理学 2021-08-16 A. S. Agrawal , Laxmipriya Pati , S. K. Tripathy , B. Mishra

In this paper, we ponder observational constraints on the modified $f(R,T)$ gravity, where the gravitational action is a function of Ricci scalar $R$ plus the trace of the energy-momentum tensor $T$, regarding the functional form…

广义相对论与量子宇宙学 · 物理学 2025-05-01 Mahnaz Asghari , Ahmad Sheykhi

In this paper, we have explored the field equations of f(T, B) gravity as an extension of teleparallel gravity in an isotropic and homogeneous space time. In the basic formalism developed, the dynamical parameters are derived by…

广义相对论与量子宇宙学 · 物理学 2024-09-27 S. A. Kadam , Jackson Levi Said , B. Mishra

This paper analyses the cosmological consequences of a modified theory of gravity whose action integral is built from a linear combination of the Ricci scalar $R$ and a quadratic term in the covariant derivative of $R$. The resulting…

广义相对论与量子宇宙学 · 物理学 2015-12-31 R. R. Cuzinatto , C. A. M. de Melo , L. G. Medeiros , P. J. Pompeia

We consider a gravitational model in which matter is non-minimally coupled to geometry, with the effective Lagrangian of the gravitational field being given by an arbitrary function of the Ricci scalar, the trace of the matter…

广义相对论与量子宇宙学 · 物理学 2024-11-18 Zahra Haghani , Tiberiu Harko , Francisco S. N. Lobo , Hamid Reza Sepangi , Shahab Shahidi

The problem of matching different regions of spacetime in order to construct inhomogeneous cosmological models is investigated in the context of Lagrangian theories of gravity constructed from general analytic functions f(R), and from…

广义相对论与量子宇宙学 · 物理学 2013-04-24 Timothy Clifton , Peter Dunsby , Rituparno Goswami , Anne Marie Nzioki

Gravitational baryogenesis is one of the mechanisms which help us to explore more about our early universe, especially baryon-anti-baryon asymmetry. As we know, modified theories of gravity are very successful in describing the present…

广义相对论与量子宇宙学 · 物理学 2023-05-23 Sai Swagat Mishra , Sanjay Mandal , P. K. Sahoo

In this work, we use reconstruction methods to obtain cosmological solutions in the recently developed scalar-tensor representation of $f(R,T)$ gravity. Assuming that matter is described by an isotropic perfect fluid and the spacetime is…

广义相对论与量子宇宙学 · 物理学 2022-03-15 Tiago B. Gonçalves , João Luís Rosa , Francisco S. N. Lobo

In a recent paper [1] (PRL 98,131302,2007) we have shown that f(R)=R + mu R^{n} modified gravity dark energy models are not cosmologically viable because during the matter era that precedes the accelerated stage the cosmic expansion is…

天体物理学 · 物理学 2008-11-26 Luca Amendola , David Polarski , Shinji Tsujikawa