{"title":"Squeezed Thermal State Representation of the Inflaton and Particle Production in Bianchi Type-I Universe","authors":"Karam Chand","doi":"10.1134/S0202289323030040","DOIUrl":null,"url":null,"abstract":"<p>We use a single-mode squeezed thermal vacuum state formalism and examine the nature of a massive homogeneous scalar field minimally coupled to gravity in the framework of semiclassical gravity in a Bianchi type-I universe. We have obtained an estimate leading solution to the semiclassical Einstein equation for the Bianchi type-I universe showing that each scale factor in its respective direction obeys <span>\\(t^{2/3}\\)</span> power-law expansion. The mechanism of nonclassical thermal cosmological particle production is also analyzed in the Bianchi type-I universe.</p>","PeriodicalId":583,"journal":{"name":"Gravitation and Cosmology","volume":null,"pages":null},"PeriodicalIF":1.2000,"publicationDate":"2023-09-04","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/S0202289323030040","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
We use a single-mode squeezed thermal vacuum state formalism and examine the nature of a massive homogeneous scalar field minimally coupled to gravity in the framework of semiclassical gravity in a Bianchi type-I universe. We have obtained an estimate leading solution to the semiclassical Einstein equation for the Bianchi type-I universe showing that each scale factor in its respective direction obeys \(t^{2/3}\) power-law expansion. The mechanism of nonclassical thermal cosmological particle production is also analyzed in the Bianchi type-I 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