{"title":"Cosmological dynamics","authors":"A. Steane","doi":"10.1093/oso/9780192895646.003.0023","DOIUrl":null,"url":null,"abstract":"The chapter deals with the large-scale dynamics of the universe. First the Friedmann equations are obtained from the Einstein field equation, and they are interpreted with the aid of a Newtonian comparison. Then the application to the universe modelled as a collection of ideal fluids is described. Density parameters and the equation of the state are defined, and the main features of the evolution of matter, radiation and the vacuum are obtained. Analytic solutuions in various simple cases are found. Dark matter and dark energy are defined through their observational evidence. The particle horizon is defined and discussed. The density and temperature at last scattering are calculated by a model involving Thomson scattering, expansion, and the Saha equation.","PeriodicalId":365636,"journal":{"name":"Relativity Made Relatively Easy Volume 2","volume":"12 1","pages":"0"},"PeriodicalIF":0.0000,"publicationDate":"2021-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Relativity Made Relatively Easy Volume 2","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1093/oso/9780192895646.003.0023","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 0
Abstract
The chapter deals with the large-scale dynamics of the universe. First the Friedmann equations are obtained from the Einstein field equation, and they are interpreted with the aid of a Newtonian comparison. Then the application to the universe modelled as a collection of ideal fluids is described. Density parameters and the equation of the state are defined, and the main features of the evolution of matter, radiation and the vacuum are obtained. Analytic solutuions in various simple cases are found. Dark matter and dark energy are defined through their observational evidence. The particle horizon is defined and discussed. The density and temperature at last scattering are calculated by a model involving Thomson scattering, expansion, and the Saha equation.