{"title":"Anisotropies of diffusive ultra-high energy cosmic rays in f(R) gravity theory","authors":"Swaraj Pratim Sarmah, Umananda Dev Goswami","doi":"10.1016/j.astropartphys.2024.103005","DOIUrl":null,"url":null,"abstract":"<div><p>Understanding the anisotropy of ultra high-energy cosmic rays (UHECRs) is crucial for unravelling the origins and propagation mechanisms of these enigmatic particles. In this work, we studied the dipolar anisotropy of UHECRs in the diffusive regime by considering three cosmological models: the standard <span><math><mi>Λ</mi></math></span>CDM model, <span><math><mrow><mi>f</mi><mrow><mo>(</mo><mi>R</mi><mo>)</mo></mrow></mrow></math></span> gravity power-law model and the Starobinsky model. This work aims to see the role of the <span><math><mrow><mi>f</mi><mrow><mo>(</mo><mi>R</mi><mo>)</mo></mrow></mrow></math></span> gravity theory in understanding the anisotropy of UHECRs without condoning the standard cosmology. We found that the amplitude of the dipolar anisotropy is sensitive to these cosmological models, with the <span><math><mrow><mi>f</mi><mrow><mo>(</mo><mi>R</mi><mo>)</mo></mrow></mrow></math></span> power-law model predicting the largest amplitude, while the <span><math><mi>Λ</mi></math></span>CDM model predicting the smallest amplitude at most of the energies in the range considered. The predicted amplitude of the Starobinsky model lies within the range of the <span><math><mi>Λ</mi></math></span>CDM one. This work not only provides a way for exploration of UHECRs anisotropy within different cosmological contexts but also may pave the way for new avenues of research at the intersection of high-energy astrophysics.</p></div>","PeriodicalId":55439,"journal":{"name":"Astroparticle Physics","volume":"163 ","pages":"Article 103005"},"PeriodicalIF":4.2000,"publicationDate":"2024-06-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Astroparticle Physics","FirstCategoryId":"101","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0927650524000823","RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ASTRONOMY & ASTROPHYSICS","Score":null,"Total":0}
引用次数: 0
Abstract
Understanding the anisotropy of ultra high-energy cosmic rays (UHECRs) is crucial for unravelling the origins and propagation mechanisms of these enigmatic particles. In this work, we studied the dipolar anisotropy of UHECRs in the diffusive regime by considering three cosmological models: the standard CDM model, gravity power-law model and the Starobinsky model. This work aims to see the role of the gravity theory in understanding the anisotropy of UHECRs without condoning the standard cosmology. We found that the amplitude of the dipolar anisotropy is sensitive to these cosmological models, with the power-law model predicting the largest amplitude, while the CDM model predicting the smallest amplitude at most of the energies in the range considered. The predicted amplitude of the Starobinsky model lies within the range of the CDM one. This work not only provides a way for exploration of UHECRs anisotropy within different cosmological contexts but also may pave the way for new avenues of research at the intersection of high-energy astrophysics.
期刊介绍:
Astroparticle Physics publishes experimental and theoretical research papers in the interacting fields of Cosmic Ray Physics, Astronomy and Astrophysics, Cosmology and Particle Physics focusing on new developments in the following areas: High-energy cosmic-ray physics and astrophysics; Particle cosmology; Particle astrophysics; Related astrophysics: supernova, AGN, cosmic abundances, dark matter etc.; Gravitational waves; High-energy, VHE and UHE gamma-ray astronomy; High- and low-energy neutrino astronomy; Instrumentation and detector developments related to the above-mentioned fields.