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相关论文: Bounding f(R,T) gravity by particle creation

200 篇论文

In this paper, a bouncing cosmological scenario is studied in the background of a flat FLRW model with a specific parametrized hyperbolic form of scale factor $ a $ in terms of $ t $, where $ \lambda $ is taken as the model parameter. This…

广义相对论与量子宇宙学 · 物理学 2022-08-12 J. K. Singh , Shaily , Kazuharu Bamba

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 construct perturbative quantum gravity in a generally covariant way. In particular our construction is background independent. It is based on the locally covariant approach to quantum field theory and the renormalized Batalin-Vilkovisky…

数学物理 · 物理学 2015-11-30 Romeo Brunetti , Klaus Fredenhagen , Katarzyna Rejzner

In this paper we investigate the Yokoyama gaugeon formalism for perturbative quantum gravity in a general curved spacetime. Within the gaugeon formalism, we extend the configuration space by introducing vector gaugeon fields describing a…

高能物理 - 理论 · 物理学 2014-02-14 Sudhaker Upadhyay

Off-diagonal vacuum and nonvacuum configurations in Einstein gravity can mimic physical effects of modified gravitational theories of $f(R,T,R_{\mu \nu}T^{\mu \nu})$ type. To prove this statement, exact and approximate solutions are…

广义相对论与量子宇宙学 · 物理学 2015-07-01 Emilio Elizalde , Sergiu I. Vacaru

In this article, we considered the bulk viscous fluid in the formalism of modified gravity in which the general form of a gravitational action is $f(R, T)$ function, where $R$ is the curvature scalar and $T$ is the trace of the energy…

广义相对论与量子宇宙学 · 物理学 2017-08-02 G. C. Samanta , R. Myrzakulov

We investigate the existence of black bounce solutions in $2+1$ dimensions within the framework of $f(R)$ gravity. We analyze whether black bounce geometries originally obtained in general relativity can be consistently generalized to…

广义相对论与量子宇宙学 · 物理学 2026-04-09 Marcos V. de S. Silva , Manuel E. Rodrigues , C. F. S. Pereira

It is well known that one cannot apply a conformal transformation to $f(T)$ gravity to obtain a minimally coupled scalar field model, and thus no Einstein frame exists for $f(T)$ gravity. Furthermore nonminimally coupled "teleparallel dark…

广义相对论与量子宇宙学 · 物理学 2016-05-05 Matthew Wright

In this work we consider a cosmological scenario in which the Universe contracts initially having a bouncing-like behavior, and accordingly after it bounces off, it decelerates following a matter dominated like evolution and at very large…

广义相对论与量子宇宙学 · 物理学 2020-12-02 S. D. Odintsov , V. K. Oikonomou , Tanmoy Paul

The $f(R)$ gravity can be cast into the form of a scalar-tensor theory, and scalar degree of freedom can be suppressed in high-density regions by the chameleon mechanism. In this article, for the general $f(R)$ gravity, using a…

宇宙学与河外天体物理 · 物理学 2018-01-04 Tan Liu , Xing Zhang , Wen Zhao

Recently a $f(T)$ gravity based on the modification of the teleparallel gravity was proposed to explain the accelerated expansion of the universe without the need of dark energy. We use observational data from Type Ia Supernovae, Baryon…

广义相对论与量子宇宙学 · 物理学 2016-06-06 Jing-Zhao Qi , Rong-Jia Yang , Ming-Jian Zhang , Wen-Biao Liu

The dynamical aspects of some accelerating models are investigated in the framework of an extension of symmetric teleparllel gravity dubbed as f(Q,T) gravity. In this gravity theory, the usual Ricci tensor in the geometrical action is…

广义相对论与量子宇宙学 · 物理学 2021-07-28 Laxmipriya Pati , B. Mishra , S. K. Tripathy

We confront $f(T,T_G)$ gravity, with Big Bang Nucleosynthesis (BBN) requirements. The former is obtained using both the torsion scalar, as well as the teleparallel equivalent of the Gauss-Bonnet term, in the Lagrangian, resulting to…

广义相对论与量子宇宙学 · 物理学 2022-09-20 Petros Asimakis , Emmanuel N. Saridakis , Spyros Basilakos , Kuralay Yesmakhanova

We derive an exact $f(T)$ gravity in the absence of ordinary matter in Friedmann-Robertson-Walker (FRW) universe, where $T$ is the teleparallel torsion scalar. We show that vanishing of the energy-momentum tensor $\mathcal{T}^{\mu \nu}$ of…

高能物理 - 理论 · 物理学 2016-10-19 W. El Hanafy , G. L. Nashed

We reconstruct $F(R)$ gravity models with exponential and power-law forms of the scale factor in which bounce cosmology can be realized. We explore the stability of the reconstructed models with analyzing the perturbations from the…

高能物理 - 理论 · 物理学 2014-01-10 Kazuharu Bamba , Andrey N. Makarenko , Alexandr N. Myagky , Shin'ichi Nojiri , Sergei D. Odintsov

We review the recent literature on modified theories of gravity in the Palatini approach. After discussing the motivations that lead to consider alternatives to Einstein's theory and to treat the metric and the connection as independent…

广义相对论与量子宇宙学 · 物理学 2011-05-09 Gonzalo J. Olmo

In this work, we introduce a novel set of asymptotically flat wormhole solutions within the framework of $f(R,T)$ theory of gravity. Considering a linear $f(R,T)=R+ 2\lambda T$ form, we show that a wide variety of wormhole solutions with…

广义相对论与量子宇宙学 · 物理学 2024-08-09 Sara Rastgoo , Foad Parsaei

This study systematically investigates the cosmological dynamics of two well-motivated functional forms in $f(T,B)$ gravity within a flat Friedmann-Lema\^{i}tre-Robertson-Walker (FLRW) universe. Here $T$ denotes the torsion scalar and $B$…

广义相对论与量子宇宙学 · 物理学 2026-02-16 Jianwen Liu , Fabao Gao , Aqeela Razzaq

In the present analysis, we explore a new version of dark energy called Barrow holographic dark energy within the framework modified gravity called $f(Q,T)$ gravity by adopting the simple homogeneous, isotropic, and spatially flat…

广义相对论与量子宇宙学 · 物理学 2024-08-09 N. Myrzakulov , S. H. Shekh , Anirudh Pradhan , K Ghaderi

The dynamics of perfect fluid as a source in the context of modified gravity, specifically $f(Q,T)$ gravity, are examined within the Friedmann-Lema\^itre-Robertson-Walker (FLRW) cosmological model. This gravity is a generic function of the…

广义相对论与量子宇宙学 · 物理学 2024-08-02 S. H. Shekh , Anirudh Pradhan , S. P. Gaikwad , K. R. Mule