Anisotropic Bianchi Type V Model with Variable \(\boldsymbol{\Lambda}\) and \(\boldsymbol{G}\): Cosmological Aspects and Singularity Analysis

IF 1 4区 物理与天体物理 Q3 ASTRONOMY & ASTROPHYSICS
S. Kotambkar, Prerna Parkhi, G. P. Singh
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引用次数: 0

Abstract

We consider an anisotropic space-time model and explore the universe evolution using analytical solutions of directional scale factors. In the Bianchi type V space-time framework, a new set of exact solutions of Einstein’s field equations with dynamical gravitational and cosmological constants have been obtained. The time-dependent expansion scalar is used to illustrate the observational compatibility with the Cosmic chronometer data. The cosmographic parameters are studied using the best-fit parameter values. The model yields a consistent evolution as compared to the \(\Lambda\)–cold dark matter model at low redshift. Further, we study the existence of finite-time singularities in the anisotropic space-time. The universe evolution with the linear equation of state has been probed for different aspects, such as the behavior of physical parameters and dissipation of anisotropy. The model may explain the accelerating universe expansion with vanishing anisotropy at late times.

Abstract Image

Abstract Image

具有变量\(\boldsymbol{\Lambda}\)和\(\boldsymbol{G}\)的各向异性Bianchi V型模型:宇宙学方面和奇点分析
我们考虑了一个各向异性的时空模型,并利用方向尺度因子的解析解来探索宇宙演化。在Bianchi V型时空框架下,得到了具有动态引力常数和宇宙学常数的爱因斯坦场方程的一组新的精确解。时间相关的膨胀标量被用来说明观测与宇宙天文钟数据的兼容性。用最佳拟合参数值来研究宇宙学参数。与低红移的\(\Lambda\) -冷暗物质模型相比,该模型产生了一致的演化。进一步研究了各向异性时空中有限时间奇点的存在性。从物理参数的行为和各向异性的耗散等不同方面探讨了线性状态方程下的宇宙演化。该模型可以解释宇宙在后期加速膨胀时各向异性消失的现象。
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来源期刊
Gravitation and Cosmology
Gravitation and Cosmology ASTRONOMY & ASTROPHYSICS-
CiteScore
1.70
自引率
22.20%
发文量
31
审稿时长
>12 weeks
期刊介绍: Gravitation and Cosmology is a peer-reviewed periodical, dealing with the full range of topics of gravitational physics and relativistic cosmology and published under the auspices of the Russian Gravitation Society and Peoples’ Friendship University of Russia. The journal publishes research papers, review articles and brief communications on the following fields: theoretical (classical and quantum) gravitation; relativistic astrophysics and cosmology, exact solutions and modern mathematical methods in gravitation and cosmology, including Lie groups, geometry and topology; unification theories including gravitation; fundamental physical constants and their possible variations; fundamental gravity experiments on Earth and in space; related topics. It also publishes selected old papers which have not lost their topicality but were previously published only in Russian and were not available to the worldwide research community
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