{"title":"Homogeneous spacetime with shear viscosity","authors":"Inyong Cho and Rajibul Shaikh","doi":"10.1088/1475-7516/2024/07/025","DOIUrl":null,"url":null,"abstract":"We study the homogeneous and anisotropic evolution of Bianchi type-I spacetime driven by perfect fluid with shear viscosity. We obtain exact solutions by considering the simplest form of the equation of state wherein the pressure and the shear stress are proportional to the energy density individually. A special case of our general solutions represent Bianchi type-VII cosmology. We analyse the singularity structure of the solutions and its connection with various energy conditions. We find that the initial singularity can be removed only for the Bianchi type-VII. We also analyse the late-time behaviour of the solutions and find that, compared to the usual Friedmann universe, the spacetime expands less rapidly and the energy density drops faster.","PeriodicalId":15445,"journal":{"name":"Journal of Cosmology and Astroparticle Physics","volume":null,"pages":null},"PeriodicalIF":5.3000,"publicationDate":"2024-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Cosmology and Astroparticle Physics","FirstCategoryId":"101","ListUrlMain":"https://doi.org/10.1088/1475-7516/2024/07/025","RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ASTRONOMY & ASTROPHYSICS","Score":null,"Total":0}
引用次数: 0
Abstract
We study the homogeneous and anisotropic evolution of Bianchi type-I spacetime driven by perfect fluid with shear viscosity. We obtain exact solutions by considering the simplest form of the equation of state wherein the pressure and the shear stress are proportional to the energy density individually. A special case of our general solutions represent Bianchi type-VII cosmology. We analyse the singularity structure of the solutions and its connection with various energy conditions. We find that the initial singularity can be removed only for the Bianchi type-VII. We also analyse the late-time behaviour of the solutions and find that, compared to the usual Friedmann universe, the spacetime expands less rapidly and the energy density drops faster.
期刊介绍:
Journal of Cosmology and Astroparticle Physics (JCAP) encompasses theoretical, observational and experimental areas as well as computation and simulation. The journal covers the latest developments in the theory of all fundamental interactions and their cosmological implications (e.g. M-theory and cosmology, brane cosmology). JCAP''s coverage also includes topics such as formation, dynamics and clustering of galaxies, pre-galactic star formation, x-ray astronomy, radio astronomy, gravitational lensing, active galactic nuclei, intergalactic and interstellar matter.