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相关论文: Constraining the $f(R,T) = R + 2\lambda T$ cosmolo…

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In this paper, we have studied the dynamical aspects of the cosmological model of the Universe in the Weyl type $f(Q,T)$ gravity, which is an extension of symmetric teleparallel gravity. The non-metricity scalar $Q$ has been expressed in…

广义相对论与量子宇宙学 · 物理学 2023-06-02 Rahul Bhagat , S. A. Narawade , B. Mishra

In this article, the bulk viscosity is introduced in a modified gravity model. The gravitational action has a general $f(R,T)$ form, where $R$ and $ T $ are the curvature scalar and the trace of energy momentum tensor respectively. An…

广义相对论与量子宇宙学 · 物理学 2020-10-02 Simran Arora , Xin-he Meng , S. K. J. Pacif , P. K. Sahoo

In the current study, we investigate a scalar field cosmological model with Lyra's geometry to explain the present cosmic expansion in a homogeneous and isotropic flat FRW universe. In Einstein's field equations, we presupposed a variable…

广义相对论与量子宇宙学 · 物理学 2025-11-19 Vinod Kumar Bhardwaj , Anil Kumar Yadav , Lalit Kumar Gupta , Rajendra Prasad , Sudhir Kumar Srivastava

In this paper, we have considered a quadratic variation of the deceleration parameter ($q$) as a function of cosmic time ($t$) which describes a smooth transition from the decelerating phase of the Universe to an accelerating one and also…

广义相对论与量子宇宙学 · 物理学 2022-06-30 Ritika Nagpal , Shibesh Kumar Jas Pacif

A new kind of evolution for cyclic models in which the Hubble parameter oscillates and keeps positive has been explored in a specific $f(R,T)$ gravity reconstruction. A singularity-free cyclic universe with negative varying cosmological…

广义相对论与量子宇宙学 · 物理学 2019-02-11 Nasr Ahmed , Sultan Z. Alamri

Determining the mechanism behind the current cosmic acceleration constitutes a major question nowadays in theoretical physics. If the dark energy route is taken, this problem may potentially bring to light new insights not only in Cosmology…

天体物理学 · 物理学 2009-07-09 E. M. Barboza , J. S. Alcaniz

Context. Explaining the accelerated expansion of the Universe is one of the fundamental challenges in physics today. Cosmography provides information about the evolution of the universe derived from measured distances, assuming only that…

宇宙学与河外天体物理 · 物理学 2016-10-05 Marek Demianski , Ester Piedipalumbo , Disha Sawant , Lorenzo Amati

In the context of f(R, T) gravity theory for the flat Friedmann Lemaitre Robertson Walker (FLRW) model, the accelerating expansion of the universe is investigated using a specific form of the emergent Hubble parameter. Datasets from H(z),…

广义相对论与量子宇宙学 · 物理学 2025-01-16 N. Myrzakulov , S. H. Shekh , Anirudh Pradhan , Archana Dixit

We have explored a transitioning cosmic model, depicting late-time accelerated expansion in $f(R,T^{\phi})$ theory of gravity for an isotropic and homogeneous universe, where the trace of energy-momentum tensor $T^{\phi}$ is the function of…

广义相对论与量子宇宙学 · 物理学 2024-03-29 Bhojraj Singh Jayas , Vinod Kumar Bhardwaj

We investigate the cosmological implications of $f(Q,C)$ gravity with $f(Q,C)=\alpha Q+\beta C$, where $Q$ is the non-metricity scalar and $C$ encapsulates cosmological expansion terms. Three parameterizations of the EoS for dark energy,…

广义相对论与量子宇宙学 · 物理学 2024-11-28 Amit Samaddar , S. Surendra Singh

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

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

We analyze the cosmological solutions of $f(T,B)$ gravity using dynamical system analysis where $T$ is the torsion scalar and $B$ be the boundary term scalar. In our work, we assume two specific cosmological models. For first model, we…

广义相对论与量子宇宙学 · 物理学 2023-04-26 Amit Samaddar , S. Surendra Singh

In this research paper, we explore a well-motivated parametrization of the time-dependent deceleration parameter, characterized by a cubic form, within the context of late time cosmic acceleration. The current analysis is based on the…

广义相对论与量子宇宙学 · 物理学 2023-12-19 Madhur Khurana , Himanshu Chaudhary , Saadia Mumtaz , S. K. J. Pacif , G. Mustafa

We have studied bulk viscosity in the modified $f(Q, T)$ gravity theory formalism, where $Q$ represents the non-metricity and $T$ denotes the trace of energy-momentum tensor within a flat Friedmann-Lema\^{i}tre-Robertson-Walker metric…

广义相对论与量子宇宙学 · 物理学 2021-12-01 Simran Arora , S. K. J. Pacif , Abhishek Parida , P. K. Sahoo

This paper explores models of the FLRW universe that incorporate a time-varying cosmological term $\Lambda(t)$. Specifically, we assume a power-law form for the cosmological term as a function of the scale factor: $\Lambda(t)=\Lambda_{0}…

宇宙学与河外天体物理 · 物理学 2024-05-14 M. Koussour , N. Myrzakulov , J. Rayimbaev

Recent studies indicate that, near equilibrium condition could not be maintained for bulk viscous matter models during the accelerated expansion of the universe in the context of Einstein's gravity, without including the cosmological…

广义相对论与量子宇宙学 · 物理学 2023-03-28 Vishnu A Pai , Titus K Mathew

In the last dozen years a wide and variegated mass of observational data revealed that the universe is now expanding at an accelerated rate. In the absence of a well-based theory to interpret the observations, cosmography provides…

宇宙学与河外天体物理 · 物理学 2015-09-30 Ester Piedipalumbo , Enrica Della Moglie , Roberto Cianci

In this paper, we investigate the accelerating phase of the Universe within the context of $f(R,L_m,T)$ gravity theory, where $R$, $L_m$, and $T$ represent the Ricci scalar, matter Lagrangian, and the trace of the energy-momentum tensor,…

广义相对论与量子宇宙学 · 物理学 2025-11-19 V. A. Kshirsagar , A. S. Agrawal , S. A. Kadam , Vishwajeet S. Goswami

In this paper, we explore the model of $f(Q,T)$ gravity, an extension of symmetric teleparallel gravity where the nonmetricity scalar $Q$ is non-minimally coupled to the trace of the energy-momentum tensor $T$. To ensure general covariance…

广义相对论与量子宇宙学 · 物理学 2025-09-09 Rahul Bhagat , Santosh V. Lohakare , B. Mishra