{"title":"Bispectrum from five-dimensional inflation","authors":"Ignatios Antoniadis, Auttakit Chatrabhuti, Jules Cunat, Hiroshi Isono","doi":"10.1007/JHEP08(2025)163","DOIUrl":null,"url":null,"abstract":"<p>It was proposed that five-dimensional (5D) inflation can blow up the size of a compact dimension from the 5D Planck length to the micron size, as required by the dark dimension proposal, relating the weakness of the actual gravitational force to the size of the observable universe. Moreover, it was shown that 5D inflation can generate the (approximate) flat power spectrum of primordial density fluctuations consistent with present observations. Here we compute the bispectrum of primordial scalar perturbations and show that unlike the power spectrum, it differs from the four-dimensional case at all angular distances, due to the fact that in contrast to global dilatations, invariance under special conformal transformations is not restored at late times. Moreover there is an additional enhancement in the squeezed limit.</p>","PeriodicalId":635,"journal":{"name":"Journal of High Energy Physics","volume":"2025 8","pages":""},"PeriodicalIF":5.5000,"publicationDate":"2025-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/JHEP08(2025)163.pdf","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of High Energy Physics","FirstCategoryId":"101","ListUrlMain":"https://link.springer.com/article/10.1007/JHEP08(2025)163","RegionNum":1,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"Physics and Astronomy","Score":null,"Total":0}
引用次数: 0
Abstract
It was proposed that five-dimensional (5D) inflation can blow up the size of a compact dimension from the 5D Planck length to the micron size, as required by the dark dimension proposal, relating the weakness of the actual gravitational force to the size of the observable universe. Moreover, it was shown that 5D inflation can generate the (approximate) flat power spectrum of primordial density fluctuations consistent with present observations. Here we compute the bispectrum of primordial scalar perturbations and show that unlike the power spectrum, it differs from the four-dimensional case at all angular distances, due to the fact that in contrast to global dilatations, invariance under special conformal transformations is not restored at late times. Moreover there is an additional enhancement in the squeezed limit.
期刊介绍：
The aim of the Journal of High Energy Physics (JHEP) is to ensure fast and efficient online publication tools to the scientific community, while keeping that community in charge of every aspect of the peer-review and publication process in order to ensure the highest quality standards in the journal.
Consequently, the Advisory and Editorial Boards, composed of distinguished, active scientists in the field, jointly establish with the Scientific Director the journal''s scientific policy and ensure the scientific quality of accepted articles.
JHEP presently encompasses the following areas of theoretical and experimental physics:
Collider Physics
Underground and Large Array Physics
Quantum Field Theory
Gauge Field Theories
Symmetries
String and Brane Theory
General Relativity and Gravitation
Supersymmetry
Mathematical Methods of Physics
Mostly Solvable Models
Astroparticles
Statistical Field Theories
Mostly Weak Interactions
Mostly Strong Interactions
Quantum Field Theory (phenomenology)
Strings and Branes
Phenomenological Aspects of Supersymmetry
Mostly Strong Interactions (phenomenology).
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号
