{"title":"Bouncing cosmology and the dynamical stability analysis in f(R,Lm)-gravity","authors":"Shaily , J.K. Singh , Dimple Sethi , Rita Rani , Kazuharu Bamba","doi":"10.1016/j.nuclphysb.2025.116854","DOIUrl":null,"url":null,"abstract":"<div><div>We study the bouncing cosmology in the <span><math><mi>f</mi><mo>(</mo><mi>R</mi><mo>,</mo><msub><mrow><mi>L</mi></mrow><mrow><mi>m</mi></mrow></msub><mo>)</mo></math></span> theory of gravity. In this model, we consider a specific function of <span><math><mi>f</mi><mo>(</mo><mi>R</mi><mo>,</mo><msub><mrow><mi>L</mi></mrow><mrow><mi>m</mi></mrow></msub><mo>)</mo></math></span> which contains the higher order curvature term along with the matter Lagrangian. Here, we parameterize the Hubble parameter with the motivation that it creates a model with bouncing behavior and solves the initial singularity problem during the universe's early evolution. This model achieves a bounce instead, where the universe rapidly contracts and then quickly expands again. The EoS parameter crosses the quintom line in the vicinity of the bouncing position indicating significant changes in the energy density, isotropic pressure, and temperature in the model. The model is highly unstable near the bouncing point. Finally, we analyze the model's dynamic stability in the neighborhood of the bouncing point by examining the sound velocity and the adiabatic index depictions.</div></div>","PeriodicalId":54712,"journal":{"name":"Nuclear Physics B","volume":"1013 ","pages":"Article 116854"},"PeriodicalIF":2.5000,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Nuclear Physics B","FirstCategoryId":"101","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S055032132500063X","RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"PHYSICS, PARTICLES & FIELDS","Score":null,"Total":0}
引用次数: 0
Abstract
We study the bouncing cosmology in the theory of gravity. In this model, we consider a specific function of which contains the higher order curvature term along with the matter Lagrangian. Here, we parameterize the Hubble parameter with the motivation that it creates a model with bouncing behavior and solves the initial singularity problem during the universe's early evolution. This model achieves a bounce instead, where the universe rapidly contracts and then quickly expands again. The EoS parameter crosses the quintom line in the vicinity of the bouncing position indicating significant changes in the energy density, isotropic pressure, and temperature in the model. The model is highly unstable near the bouncing point. Finally, we analyze the model's dynamic stability in the neighborhood of the bouncing point by examining the sound velocity and the adiabatic index depictions.
期刊介绍:
Nuclear Physics B focuses on the domain of high energy physics, quantum field theory, statistical systems, and mathematical physics, and includes four main sections: high energy physics - phenomenology, high energy physics - theory, high energy physics - experiment, and quantum field theory, statistical systems, and mathematical physics. The emphasis is on original research papers (Frontiers Articles or Full Length Articles), but Review Articles are also welcome.