{"title":"Prediction of Super-Exponentially Accelerated Universe in a Friedmann–Lemaitre–Robertson–Walker Metric","authors":"Giridhari Deogharia, Sandip Dutta","doi":"10.1134/S0202289324700221","DOIUrl":null,"url":null,"abstract":"<p>A coupled model of variable-modified Chaplygin gas (as a candidate of dark energy) and dark matter is assumed in the background of the Friedmann–Lemaitre–Robertson–Walker universe. Firstly, a two-dimensional autonomous dynamical system is considered for a flat universe after determining some suitable dimensionless parameters. The evolution of those parameters along with the deceleration parameter is observed. Next, the evolution of matter and energy density parameters is studied for variational coupling parameters. Phase portrait analysis is performed to explain the present as well as future expansion of the universe. Secondly, both three- and four-dimensional dynamic systems are constructed when the evolution of spatially homogeneous and isotropic model of the universe is considered, which includes the cosmological constant and three-curvature symmetry surfaces. For the three-dimensional system, updates of dimensionless parameters along with deceleration parameters are analyzed for variational coupling parameters with respect to progression of the universe. Again, the evolution of the deceleration parameter is studied for different values of <span>\\(n\\)</span>. Stability analysis is carried out for the concerned dynamical system with the help of eigenvalues. The four-dimensional dynamical system is remarkable as it helps to study the evolution of <span>\\(\\Lambda\\)</span> density along with other parameters. Lastly, for the concerned dynamical system, the evolution of matter and energy density parameters is analyzed for different values of <span>\\(c\\)</span> to study whether or not the coupling parameters affect the ultimate evolution of the universe.</p>","PeriodicalId":583,"journal":{"name":"Gravitation and Cosmology","volume":null,"pages":null},"PeriodicalIF":1.2000,"publicationDate":"2024-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Gravitation and Cosmology","FirstCategoryId":"4","ListUrlMain":"https://link.springer.com/article/10.1134/S0202289324700221","RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"ASTRONOMY & ASTROPHYSICS","Score":null,"Total":0}
引用次数: 0
Abstract
A coupled model of variable-modified Chaplygin gas (as a candidate of dark energy) and dark matter is assumed in the background of the Friedmann–Lemaitre–Robertson–Walker universe. Firstly, a two-dimensional autonomous dynamical system is considered for a flat universe after determining some suitable dimensionless parameters. The evolution of those parameters along with the deceleration parameter is observed. Next, the evolution of matter and energy density parameters is studied for variational coupling parameters. Phase portrait analysis is performed to explain the present as well as future expansion of the universe. Secondly, both three- and four-dimensional dynamic systems are constructed when the evolution of spatially homogeneous and isotropic model of the universe is considered, which includes the cosmological constant and three-curvature symmetry surfaces. For the three-dimensional system, updates of dimensionless parameters along with deceleration parameters are analyzed for variational coupling parameters with respect to progression of the universe. Again, the evolution of the deceleration parameter is studied for different values of \(n\). Stability analysis is carried out for the concerned dynamical system with the help of eigenvalues. The four-dimensional dynamical system is remarkable as it helps to study the evolution of \(\Lambda\) density along with other parameters. Lastly, for the concerned dynamical system, the evolution of matter and energy density parameters is analyzed for different values of \(c\) to study whether or not the coupling parameters affect the ultimate evolution of the universe.
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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