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The expansion of the Universe in $f(R,T)$ gravity is studied. We consider functions of the form $f(R,T)=R+\lambda T^\epsilon$ where $\epsilon<1$. We find that for all models with $\epsilon<0$, the Universe transitions to exponential growth…

广义相对论与量子宇宙学 · 物理学 2026-03-26 Vincent R. Siggia , Eric D. Carlson , P. Lee Pryor

We investigated the stability condition in $f(T,\phi)$ gravity theory for considering two models by using dynamical system. We assume the forms of $G(T)$ are $(i)$ $G(T)$ = $\alpha T+\frac{\beta}{T}$, $(ii)$ $G(T)$ = $\zeta T$ ln$(\psi T)$,…

广义相对论与量子宇宙学 · 物理学 2023-06-14 Amit Samaddar , S. Surendra Singh

We conduct a thorough examination of cosmological parameters within the context of $f(R)$ gravity coupled with neutrinos, leveraging a diverse array of observational datasets, including Cosmic Microwave Background (CMB), Cosmic Chronometers…

宇宙学与河外天体物理 · 物理学 2025-01-14 Muhammad Yarahmadi , Amin Salehi , Kazuharu Bamba , Hosein Farajollahi

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

In this paper we present cosmological constraints on several well-known $f(R)$ models, but also on a new class of models that are variants of the Hu-Sawicki one of the form $f(R)=R-\frac{2\Lambda}{1+b\;y(R,\Lambda)}$, that interpolate…

宇宙学与河外天体物理 · 物理学 2018-01-29 Judit Pérez-Romero , Savvas Nesseris

Cosmology faces a pressing challenge with the Hubble constant ($H_0$) tension, where the locally measured rate of the Universe's expansion does not align with predictions from the cosmic microwave background (CMB) calibrated with…

宇宙学与河外天体物理 · 物理学 2024-02-27 Rebecca Briffa , Celia Escamilla-Rivera , Jackson Levi Said , Jurgen Mifsud

We present a unified framework that combines early- and late-Universe observations to constrain three functional realizations of f(T,B) gravity: the linear, quadratic, and general power-law models. First, constraints on deviations from the…

宇宙学与河外天体物理 · 物理学 2026-01-27 Yahia Al-Omar , Majida Nahili , Nidal Chamoun

A class of Kaluza-Klein cosmological models in $f(R,T)$ theory of gravity have been investigated. In the work, we have considered the functional $f(R,T)$ to be in the form $f(R,T)=f(R)+f(T)$ with $f(R)=\lambda R$ and $f(T)=\lambda T$. Such…

广义相对论与量子宇宙学 · 物理学 2016-07-14 P. K. Sahoo , B. Mishra , S. K. Tripathy

We explore the viable $f(R)$ gravity models in FLRW backgrounds with a free spatial curvature parameter $\Omega_{K}$. In our numerical calculation, we concentrate on the exponential $f(R)$ model of $f(R) = R - \lambda…

宇宙学与河外天体物理 · 物理学 2022-02-18 Chao-Qiang Geng , Yan-Ting Hsu , Jhih-Rong Lu

In this paper, we consider a gravitational action containing a combination of the Ricci scalar, $R$, and the topological Gauss--Bonnet term, $G$. Specifically, we study the cosmological features of a particular class of modified gravity…

广义相对论与量子宇宙学 · 物理学 2023-03-15 Francesco Bajardi , Rocco D'Agostino

We study the cosmological constraints on the variation of the Newton's constant and on post-Newtonian parameters for simple models of scalar-tensor theory of gravity beyond the extended Jordan-Brans-Dicke theory. We restrict ourselves to an…

宇宙学与河外天体物理 · 物理学 2020-02-07 M. Rossi , M. Ballardini , M. Braglia , F. Finelli , D. Paoletti , A. A. Starobinsky , C. Umiltà

In this paper we place observational constraints on the well-known $\gamma$-gravity $f(R)$ model using the latest cosmological data, namely we use the latest growth rate, Cosmic Microwave Background, Baryon Acoustic Oscillations, Supernovae…

宇宙学与河外天体物理 · 物理学 2018-07-17 Clara Álvarez Luna , Spyros Basilakos , Savvas Nesseris

We consider a cosmological model dominated by bulk viscous matter with total bulk viscosity coefficient proportional to the velocity and acceleration of the expansion of the universe in such a way that…

广义相对论与量子宇宙学 · 物理学 2016-04-28 Athira Sasidharan , Titus K. Mathew

We explore the cosmological dynamics of a teleparallel Gauss-Bonnet gravity model defined by the torsion scalar $T$ and the torsion-based Gauss-Bonnet invariant $T_{\mathcal{G}}$, deriving modified Friedmann equations for a flat FLRW…

广义相对论与量子宇宙学 · 物理学 2026-01-16 Santosh V. Lohakare , S. K. Maurya , Aaisha Al Qassabi , B. Mishra

This paper investigates the energy bounds in modified Gauss-Bonnet gravity with anisotropic background. Locally rotationally symmetric Bianchi type ${I}$ cosmological model in $f(R,G)$ gravity is considered to meet this aim. Primarily, a…

综合物理 · 物理学 2017-12-07 M. Farasat Shamir , Ayesha Komal

Motivated by recent work on consistent fluid couplings in $f(R, T)$ gravity, we study cosmology in the nontrivial model $f(R, T) = R + \sigma R T$ using the Brown variational principle for a barotropic perfect fluid. For a flat FLRW…

广义相对论与量子宇宙学 · 物理学 2026-05-15 Davide Batic , Christian G. Boehmer , Denys Dutykh

In order to deal with a large cosmological constant a relaxation mechanism based on modified gravity has been proposed recently. By virtue of this mechanism the effect of the vacuum energy density of a given quantum field/string theory (no…

广义相对论与量子宇宙学 · 物理学 2012-01-31 Spyros Basilakos , Florian Bauer , Joan Sola

This paper examines the late-time accelerating Universe and the formation of large-scale structures within the modified symmetric teleparallel gravity framework, specifically using the $f(Q)$-gravity model, in light of recent cosmological…

广义相对论与量子宇宙学 · 物理学 2024-12-31 Shambel Sahlu , Amare Abebe

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

In this paper, the dynamical behavior of the accelerated expansion of the universe is discussed within the framework of $f(T)$ gravity, considering power law functional form of $ f(T)=\alpha (-T)^{n}$. Two distinct redshift-dependent…

广义相对论与量子宇宙学 · 物理学 2025-08-29 Shivank Pal , Romanshu Garg , Gyan Prakash Singh , Gauree Shanker