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相关论文: Cosmic anisotropy with Reduced Relativistic Gas

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We consider the case of $R^n$-gravity and perform a detailed analysis of the dynamics in Bianchi I cosmologies which exhibit {\it local rotational symmetry} (LRS). We find exact solutions and study their behaviour and stability in terms of…

广义相对论与量子宇宙学 · 物理学 2007-05-23 Jannie A. Leach , Peter K. S. Dunsby , Sante Carloni

Anisotropic Bianchi-III cosmological model is investigated with variable gravitational and cosmological constants in the framework of Einstein's general relativity. The shear scalar is considered to be proportional to the expansion scalar.…

广义相对论与量子宇宙学 · 物理学 2015-06-23 S. K. Tripathy , D. Behera , T. R. Routray

Most existing cosmological entanglement studies are focused on the isotropic Robertson-Walker (RW) spacetime. Here we go beyond this limitation and study the influence of anisotropy on entanglement generated by dynamical spacetime. Since…

广义相对论与量子宇宙学 · 物理学 2017-11-16 Roberto Pierini , Shahpoor Moradi , Stefano Mancini

The role of anisotropic components on the dark energy and the dynamics of the universe is investigated. An anisotropic dark energy fluid with different pressures along different spatial directions is assumed to incorporate the effect of…

综合物理 · 物理学 2018-04-16 B. Mishra , S. K. Tripathy , Pratik P Ray

We examine the behaviour of homogeneous, anisotropic space-times, specifically the locally rotationally symmetric Bianchi types $I$ and $VII_o$ in the presence of anisotropic matter. By finding an appropriate constant of the motion, and…

广义相对论与量子宇宙学 · 物理学 2016-04-29 David Sloan

The dynamical features of Bianchi type $VI_h$ $(BVI_h)$ universe are investigated in $f(R,T)$ theory of gravity. The field equations and the physical properties of the model are derived considering a power law expansion of the universe. The…

广义相对论与量子宇宙学 · 物理学 2018-08-09 B. Mishra , Sankarsan Tarai , S. K. Tripathy

Locally rotationally symmetric (LRS) Bianchi Type I cosmological models are examined in the presence of dynamically anisotropic dark energy and perfect fluid. We assume that the dark energy (DE) is minimally interacting, has dynamical…

广义相对论与量子宇宙学 · 物理学 2014-11-18 Ozgur Akarsu , Can B. Kilinc

Considering the Universe as a dynamic system, the understanding of its evolution is an interesting aspect of study in cosmology. Here, we investigate the anisotropic locally rotationally symmetric (LRS) Bianchi type-I (LRS-BI) spacetime…

广义相对论与量子宇宙学 · 物理学 2024-06-21 Pranjal Sarmah , Umananda Dev Goswami

We study the low energy string effective action with an exponential type dilaton potential and vanishing torsion in a Bianchi type I space-time geometry. In the Einstein and string frames the general solution of the gravitational field…

高能物理 - 理论 · 物理学 2009-10-31 Chiang-Mei Chen , T. Harko , M. K. Mak

Nonlocal RT gravity has proven effective in explaining the late-time cosmic acceleration while remaining consistent with local gravity tests. However, most previous cosmological studies of this theory have assumed an isotropic background,…

广义相对论与量子宇宙学 · 物理学 2026-03-17 Jiajun Zhou , Shuxun Tian , Zong-Hong Zhu

We have examined the cosmological actions of LRS (Locally Rationally Symmetric) Bianchi type-I universe model in $f(R,T^\psi)$ gravity. For this, we have estimated the Hubble parameter, the effective equation of state parameter…

广义相对论与量子宇宙学 · 物理学 2026-01-07 Mohit Thakre , Praveen Kumar Dhankar , Safiqul Islam , Parbati Sahoo , Farook Rahaman , Behnam Pourhassan

In the context of modified tele-parallel theory of gravity, we undertake cosmological anisotropic models and search for their solutions. Within a suitable choice of non-diagonal tetrads, the decoupled equations of motion are obtained for…

广义相对论与量子宇宙学 · 物理学 2015-06-25 M. E. Rodrigues , A. V. Kpadonou , F. Rahaman , P. J. Oliveira , M. J. S. Houndjo

The present work is related to anisotropic cosmological evolution in metric $f(R)$ theory of gravity. The initial part of the paper develops the general cosmological dynamics of homogeneous anisotropic Bianchi-I spacetime in $f(R)$…

广义相对论与量子宇宙学 · 物理学 2019-01-23 Kaushik Bhattacharya , Saikat Chakraborty

According to standard cosmology, the universe is homogeneous and isotropic at large scales. However, some anisotropies can be observed at the local scale in the universe through various ways. Here we have studied the Bianchi type I model…

广义相对论与量子宇宙学 · 物理学 2022-09-12 Pranjal Sarmah , Umananda Dev Goswami

The standard cosmological model is challenged by an ever-growing collection of observations, which invites (and stimulates) inquiry into possible additions and/or alterations. One such alteration comes from letting cosmic isotropy -- as…

广义相对论与量子宇宙学 · 物理学 2026-04-22 Robbert W. Scholtens , Marcello Seri , Holger Waalkens , Rien van de Weygaert

Anisotropic cloud string cosmological model with Bianchi type I space time is investigated in the context of general relativity. The exact solutions of Einstein field equations are obtained with when the source for energy momentum tensor is…

综合物理 · 物理学 2019-09-26 Kangujam Priyokumar Singh , Meher Daimary

We investigate the cosmological reconstruction in anisotropic universe for both homogeneous and inhomogeneous content of the universe. Special attention is attached to three interesting cases: Bianchi type-I, Bianchi type-III and…

广义相对论与量子宇宙学 · 物理学 2012-11-29 M. E. Rodrigues , M. J. S. Houndjo , D. Saez-Gomez , F. Rahaman

A spatially homogeneous and anisotropic Bianchi Type I universe has been studied with {\omega} <-1 without Big Smash. It is demonstrated that if cosmic dark energy behaves like a fluid with equation of state p = {\omega}{\rho} (p and {\rho}…

广义相对论与量子宇宙学 · 物理学 2011-08-04 Anil Kumar Yadav

The behavior near the initial singular state of the anisotropy parameter of the arbitrary type, homogeneous and anisotropic Bianchi models is considered in the framework of the brane world cosmological models. The matter content on the…

广义相对论与量子宇宙学 · 物理学 2009-11-10 T. Harko , M. K. Mak

The dynamics and evolution of Bianchi type I space-times is considered in the framework of the four-dimensional truncation of a reduced theory obtained from the N=2,D=5 supergravity. The general solution of the gravitational field equations…

高能物理 - 理论 · 物理学 2009-10-31 Chiang-Mei Chen , T. Harko , M. K. Mak