中文
相关论文

相关论文: Near Equilibrium Constraints on Bulk Viscous Model…

200 篇论文

In this manuscript, we analyze the viscous fluid cosmological model in the framework of recently proposed $f(Q)$ gravity by assuming three different forms of bulk viscosity coefficients, specifically, $(i)\zeta =\zeta_{0}+\zeta_{1}\left(…

广义相对论与量子宇宙学 · 物理学 2023-05-02 Raja Solanki , Dheeraj Singh Rana , Sanjay Mandal , P. K. Sahoo

In this article, we study the expanding nature of universe in the contest of $f(R,L_m)$ gravity theory, here $ R $ represents the Ricci scalar and $ L_m $ is the matter Lagrangian density. With a specific form of $ f(R,L_m) $, we obtain the…

广义相对论与量子宇宙学 · 物理学 2023-06-28 J. K. Singh , Shaily , Ratbay Myrzakulov , Harshna Balhara

Bulk viscous cosmological models is presented in the teleparallel ($F(T)$, where $T$ denotes torsion) gravity. In the teleparallel gravity, the Lagrangian of the gravitational action contains a general function $F(T)= T+ f(T)=(1+ \gamma)…

广义相对论与量子宇宙学 · 物理学 2025-07-22 Partha Sarathi Debnath , Chanchal Mondal , B. C. Paul

Modified theories of gravity encompass a class of $f(R)$-models that seek to elucidate the observed late time accelerated expansion of the universe. In this study, we examine a set of viable $f(R)$ models (Hu-Sawicki: two cases,…

宇宙学与河外天体物理 · 物理学 2023-12-15 Kumar Ravi , Anirban Chatterjee , Biswajit Jana , Abhijit Bandyopadhyay

In the present paper, we investigate constrained transit cosmological models in the most recent proposed modified gravity theory, $f(R,L_{m},T)$-gravity. We obtain the modified field equations for a flat homogeneous and isotropic…

广义相对论与量子宇宙学 · 物理学 2024-12-20 Dinesh Chandra Maurya

In the last century, theoretical and experimental developments have established the General Relativity theory as the most successful theory for describing the gravitational phenomenon. On the other hand, in the last two decades, multiple…

广义相对论与量子宇宙学 · 物理学 2025-02-18 Raja Solanki

In this paper, we study the model of $f(T, B)$ gravity with viscous fluid in flat-FRW metric, in which $T$ and $B$ are torsion scalar and boundary term, respectively. We obtain the Friedmann equations in the framework of modified…

广义相对论与量子宇宙学 · 物理学 2019-09-02 A. Pourbagher , Alireza Amani

We use observations related to the variation of fundamental constants, in order to impose constraints on the viable and most used $f(T)$ gravity models. In particular, for the fine-structure constant we use direct measurements obtained by…

广义相对论与量子宇宙学 · 物理学 2017-04-18 Rafael C. Nunes , Alexander Bonilla , Supriya Pan , Emmanuel N. Saridakis

In this paper, we examine the acceleration of the Universe's expansion in $F(R,T)$ gravity, where $R$ denotes the Ricci scalar and $T$ the trace of energy-momentum tensor. Indeed, the unknown nature of the source controlling this…

广义相对论与量子宇宙学 · 物理学 2024-04-25 Ahmed Errahmani , Amine Bouali , Safae Dahmani , Imad El Bojaddaini , Taoufik Ouali

The authors considered the bulk viscous fluid in $f(R, T)$ gravity within the framework of Kaluza-Klein space time. The bulk viscous coefficient $(\xi)$ expressed as $\xi=\xi_0+\xi_1\frac{\dot{a}}{a}+\xi_2\frac{\ddot{a}}{\dot{a}}$, where…

广义相对论与量子宇宙学 · 物理学 2017-04-26 G. C. Samanta , R. Myrzakulov , Parth Shah

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

The late-time acceleration of the universe remains one of the most significant open problems in modern cosmology. Modified gravity frameworks such as $f(T)$ gravity provide a geometric alternative to dark energy by attributing cosmic…

广义相对论与量子宇宙学 · 物理学 2026-05-07 Anirudh Pradhan , S. A. Salve , V. B. Raut , S. H. Shekh

We present and constrain a cosmological model which component is a pressureless fluid with bulk viscosity as an explanation for the present accelerated expansion of the universe. We study the particular model of a constant bulk viscosity…

广义相对论与量子宇宙学 · 物理学 2009-03-24 Arturo Avelino , U. Nucamendi , F. S. Guzmán

The study conducted in this research paper utilizes the $f(Q,T)$ gravity, where $Q$ represents non-metricity and $T$ represents the trace of the energy-momentum tensor, to investigate the accelerated expansion of the universe. To complete…

宇宙学与河外天体物理 · 物理学 2024-05-17 M. Koussour , N. Myrzakulov , J. Rayimbaev , A. Errehymy , Orhan Donmez

In this letter, we investigate the cosmic expansion scenario of the universe in the framework of $f(R,L_m)$ gravity theory. We consider a non-linear $f(R,L_m)$ model, specifically, $f(R,L_m)=\frac{R}{2}+L_m^n + \beta$, where $n$ and $\beta$…

广义相对论与量子宇宙学 · 物理学 2023-11-02 Lakhan V. Jaybhaye , Raja Solanki , Sanjay Mandal , P. K. Sahoo

In this paper, the dynamical behavior of the anisotropic universe has been investigated in $f(R,T)$ theory of gravity. The functional $f(R,T)$ has been rescaled in the form $f(R,T)=\mu R+\mu T$, where $R$ is the Ricci scalar and $T$ is the…

综合物理 · 物理学 2018-01-08 B. Mishra , S Tarai , S. K. J. Pacif

This study offers a comprehensive reconstruction of $f(T)$ gravity model with three distinct non-linear as well as novel forms employing a hybrid scale factor to depict the expansion history of the universe starting from early decelerated…

广义相对论与量子宇宙学 · 物理学 2026-02-17 Suraj Kumar Behera , Pratik P. Ray

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

$f(R,T)$ gravity is a widely used extended theory of gravity introduced in \cite{9} which is a straightforward generalization of $f(R)$ gravity. The action in this extended theory of gravity incorporates well motivated functional forms of…

广义相对论与量子宇宙学 · 物理学 2020-07-09 Snehasish Bhattacharjee , P. K. Sahoo

The singularity and inflationary problems have posed significant challenges for understanding the universe's origin and evolution. Bouncing cosmology has emerged as a promising alternative to standard cosmological models, offering a…

广义相对论与量子宇宙学 · 物理学 2025-07-28 A. Zhadyranova , M. Koussour , V. Zhumabekova , N. Zhusupova , S. Muminov , J. Rayimbaev