{"title":"Slow-roll inflation in f(R,T,RabTab) gravity","authors":"Zhe Feng","doi":"10.1142/s0217732324500263","DOIUrl":null,"url":null,"abstract":"<p>In the framework of <span><math altimg=\"eq-00003.gif\" display=\"inline\" overflow=\"scroll\"><mi>f</mi><mo stretchy=\"false\">(</mo><mi>R</mi><mo>,</mo><mi>T</mi><mo>,</mo><msub><mrow><mi>R</mi></mrow><mrow><mi>a</mi><mi>b</mi></mrow></msub><msup><mrow><mi>T</mi></mrow><mrow><mi>a</mi><mi>b</mi></mrow></msup><mo stretchy=\"false\">)</mo></math></span><span></span> gravity theory, the slow-roll approximation of the cosmic inflation is investigated, where <i>T</i> is the trace of the energy–momentum tensor <span><math altimg=\"eq-00004.gif\" display=\"inline\" overflow=\"scroll\"><msup><mrow><mi>T</mi></mrow><mrow><mi>a</mi><mi>b</mi></mrow></msup></math></span><span></span>, <i>R</i> and <span><math altimg=\"eq-00005.gif\" display=\"inline\" overflow=\"scroll\"><msub><mrow><mi>R</mi></mrow><mrow><mi>a</mi><mi>b</mi></mrow></msub></math></span><span></span> are the Ricci scalar and tensor, respectively. After obtaining the equations of motion of the gravitational field from the action principle in the spatially flat FLRW metric, the fundamental equations of this theory are received by introducing the inflation scalar field as the matter and taking into account only the minimum curvature-inflation coupling term. Remarkably, after taking the slow-roll approximation, the identical equations as in <span><math altimg=\"eq-00006.gif\" display=\"inline\" overflow=\"scroll\"><mi>f</mi><mo stretchy=\"false\">(</mo><mi>R</mi><mo>,</mo><mi>T</mi><mo stretchy=\"false\">)</mo></math></span><span></span> gravity with a <span><math altimg=\"eq-00007.gif\" display=\"inline\" overflow=\"scroll\"><mi>R</mi><mi>T</mi></math></span><span></span> mixing term are derived. We study several potentials of interest in different domains. We perform analytical analyzes under various approximate conditions, and present numerical results and their comparison with existing observational data at the same time. In the appendix, we analyze the behavior of the inflation scalar field under perturbation while ignoring the effect of metric perturbations. This research complements the slow-roll inflation in the modified theory of gravity.</p>","PeriodicalId":18752,"journal":{"name":"Modern Physics Letters A","volume":null,"pages":null},"PeriodicalIF":1.5000,"publicationDate":"2024-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Modern Physics Letters A","FirstCategoryId":"101","ListUrlMain":"https://doi.org/10.1142/s0217732324500263","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
In the framework of gravity theory, the slow-roll approximation of the cosmic inflation is investigated, where T is the trace of the energy–momentum tensor , R and are the Ricci scalar and tensor, respectively. After obtaining the equations of motion of the gravitational field from the action principle in the spatially flat FLRW metric, the fundamental equations of this theory are received by introducing the inflation scalar field as the matter and taking into account only the minimum curvature-inflation coupling term. Remarkably, after taking the slow-roll approximation, the identical equations as in gravity with a mixing term are derived. We study several potentials of interest in different domains. We perform analytical analyzes under various approximate conditions, and present numerical results and their comparison with existing observational data at the same time. In the appendix, we analyze the behavior of the inflation scalar field under perturbation while ignoring the effect of metric perturbations. This research complements the slow-roll inflation in the modified theory of gravity.
期刊介绍:
This letters journal, launched in 1986, consists of research papers covering current research developments in Gravitation, Cosmology, Astrophysics, Nuclear Physics, Particles and Fields, Accelerator physics, and Quantum Information. A Brief Review section has also been initiated with the purpose of publishing short reports on the latest experimental findings and urgent new theoretical developments.