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In certain modified theories of gravity, non-minimal couplings between matter and geometry lead to the nonconservation of the energy-momentum tensor. By interpreting this as an effective dissipative process, we formulate a general class of…

广义相对论与量子宇宙学 · 物理学 2026-04-27 Szőllősi Tamás-Géza

The non-conservation of the energy-momentum tensor in $f(R,T)$ gravity can be interpreted as an effective manifestation of dissipation. Motivated by this, we propose a new formulation of $f(R,T)$ gravity based on the Herglotz variational…

广义相对论与量子宇宙学 · 物理学 2026-03-20 Marek Wazny , Lehel Csillag , Miguel A. S. Pinto , Tiberiu Harko

Motivated by the growing interest in the nonmetricity-matter couplings, we develop the scalar-tensor formulation of recently introduced $f(Q,T)$ gravity, where $Q$ is the nonmetricity and $T$ is the trace of the energy-momentum tensor. The…

广义相对论与量子宇宙学 · 物理学 2025-02-27 Adam Z. Kaczmarek , João Luís Rosa , Dominik Szczȩśniak

We apply cosmological reconstruction methods to the $f(R,T)$ modified gravity, in its recently developed scalar-tensor representation. We do this analysis assuming a perfect fluid in a Friedmann-Lema\^{i}tre-Robsertson-Walker (FLRW)…

广义相对论与量子宇宙学 · 物理学 2024-07-24 Tiago B. Gonçalves , João Luís Rosa , Francisco S. N. Lobo

In this work, the $f(\mathcal{G},T)$ theory of gravity is recast in terms of the $\phi$ and $\psi$ fields within the scalar-tensor formulation, where $\mathcal{G}$ is the Gauss-Bonnet term and $T$ denotes the trace of the energy-momentum…

广义相对论与量子宇宙学 · 物理学 2023-12-20 Adam Z. Kaczmarek , Dominik Szczęśniak

In this work, we study the possibility of finite-time future cosmological singularities appearing in $f(R,T)$ gravity, where $R$ is the Ricci scalar and $T$ is the trace of the stress-energy tensor. We present the theory in both the…

广义相对论与量子宇宙学 · 物理学 2022-05-10 Tiago B. Gonçalves , João Luís Rosa , Francisco S. N. Lobo

In the context of f(R,T) theories of gravity, we study the evolution of scalar cosmological perturbations in the metric formalism. According to restrictions on the background evolution, a specific model within these theories is assumed in…

广义相对论与量子宇宙学 · 物理学 2013-06-20 F. G. Alvarenga , A. de la Cruz-Dombriz , M. J. S. Houndjo , M. E. Rodrigues , D. Sáez-Gómez

Recently, the scalar-tensor representation of $f (R,T)$ gravity was used to explore gravitationally induced particle production/annihilation. Using the framework of irreversible thermodynamics of open systems in the presence of matter…

广义相对论与量子宇宙学 · 物理学 2023-10-20 Amine Bouali , Himanshu Chaudhary , Tiberiu Harko , Francisco S. N. Lobo , Taoufik Ouali , Miguel A. S. Pinto

In this work, we use the dynamical system approach to explore the cosmological background evolution of the scalar-tensor representation of $f(R,T)$ gravity, where $R$ is the Ricci scalar and $T$ is the trace of the stress-energy tensor. The…

广义相对论与量子宇宙学 · 物理学 2024-04-04 Tiago B. Gonçalves , João Luís Rosa , Francisco S. N. Lobo

We developed the cosmological linear theory of perturbations for $f(Q,T)$ gravity, which is an extension of symmetric teleparallel gravity, with $Q$ the non-metricity and $T$ the trace of the stress-energy tensor. By considering an ansatz…

广义相对论与量子宇宙学 · 物理学 2022-03-11 Antonio Nájera , Amanda Fajardo

The present work is devoted to explore some interesting cosmological features of a newly proposed theory of gravity namely $\mathcal{F}(R,L_m,T)$ theory, where $R$ and $T$ represent the Ricci scalar and trace of energy momentum-tensor,…

广义相对论与量子宇宙学 · 物理学 2024-04-09 M. Zubair , Saira Waheed , Quratulien Muneer , M. Ahmad

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

Currently, in order to explain the accelerated expansion phase of the universe, several alternative approaches have been proposed, among which the most common are dark energy models and alternative theories of gravity. Although these…

广义相对论与量子宇宙学 · 物理学 2021-08-24 I. S. Farias , P. H. R. S. Moraes

We review the status of $f(R,T)$ cosmological models, where $T$ is the trace of the energy momentum tensor $T^{\mu\nu}$. We start focusing on the modified Friedmann equations for the minimally coupled gravitational Lagrangian of the type…

宇宙学与河外天体物理 · 物理学 2024-03-08 Ana Paula Jeakel , Jonas Pinheiro da Silva , Hermano Velten

In this study, we explored late-time cosmology within an extended class of theories based on $f(Q, L_m)$ gravity. This theory generalizes $f(Q)$ gravity by incorporating a non-minimal coupling between the non-metricity $Q$ and the matter…

宇宙学与河外天体物理 · 物理学 2024-10-07 Kairat Myrzakulov , M. Koussour , O. Donmez , A. Cilli , E. Güdekli , J. Rayimbaev

We present an extension of $f(T)$ gravity, allowing for a general coupling of the torsion scalar $T$ with the trace of the matter energy-momentum tensor $\mathcal{T}$. The resulting $f(T,\mathcal{T})$ theory is a new modified gravity, since…

广义相对论与量子宇宙学 · 物理学 2014-12-12 Tiberiu Harko , Francisco S. N. Lobo , G. Otalora , Emmanuel N. Saridakis

In this work, we study the late-time cosmological solutions of f(R,T)=g(R)+h(-T) models assuming that the conservation of the energy-momentum tensor (EMT) is violated. We perform our analysis through constructing an autonomous dynamical…

广义相对论与量子宇宙学 · 物理学 2017-08-07 Hamid Shabani , Amir Hadi ziaie

We consider an $f(Q,T)$ type gravity model in which the scalar non-metricity $Q_{\alpha \mu \nu}$ of the space-time is expressed in its standard Weyl form, and it is fully determined by a vector field $w_{\mu}$. The field equations of the…

广义相对论与量子宇宙学 · 物理学 2024-11-18 Yixin Xu , Tiberiu Harko , Shahab Shahidi , Shi-Dong Liang

In this paper we undertake the modified theory of gravity f(R,T) where R and T are the Ricci scalar and the trace of the energy momentum tensor, respectively. Imposing the conservation of the energy momentum tensor, we obtain a model about…

广义相对论与量子宇宙学 · 物理学 2015-06-30 E. H. Baffou , A. V. Kpadonou , M. E. Rodrigues , M. J. S. Houndjo , J. Tossa

We construct new classes of modified theories in which the matter sector couples with the Einstein tensor, namely we consider direct couplings of the latter to the energy-momentum tensor, and to the derivatives of its trace. We extract the…

广义相对论与量子宇宙学 · 物理学 2023-05-17 Petros Asimakis , Spyros Basilakos , Andreas Lymperis , Maria Petronikolou , Emmanuel N. Saridakis
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