{"title":"Cannibal domination and the matter power spectrum","authors":"A. Erickcek, Pranjal Ralegankar, J. Shelton","doi":"10.1103/PhysRevD.103.103508","DOIUrl":null,"url":null,"abstract":"Decoupled hidden sectors can easily and generically result in a period of cannibal domination, during which the dominant component of the Universe has an equation of state intermediate between radiation and matter due to self-heating by number-changing interactions. We present for the first time the consequences of a cannibal-dominated era prior to Big Bang Nucleosynthesis for structure formation on small scales. We find that an early cannibal-dominated era imprints a characteristic peak on the dark matter power spectrum, with scale and amplitude directly determined by the mass, lifetime, and number-changing interaction strength of the cannibal field. This enhancement to the small-scale matter power spectrum will generate early-forming dark matter microhalos, and we provide a detailed and transparent map between the properties of the cannibal species and the characteristic mass and formation time of these structures. These relations demonstrate how the internal workings of a hidden sector leave a potentially observable imprint on the matter power spectrum even if dark matter has no direct couplings to the Standard Model.","PeriodicalId":8431,"journal":{"name":"arXiv: Cosmology and Nongalactic Astrophysics","volume":"169 1","pages":""},"PeriodicalIF":0.0000,"publicationDate":"2020-08-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"17","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"arXiv: Cosmology and Nongalactic Astrophysics","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1103/PhysRevD.103.103508","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 17
Abstract
Decoupled hidden sectors can easily and generically result in a period of cannibal domination, during which the dominant component of the Universe has an equation of state intermediate between radiation and matter due to self-heating by number-changing interactions. We present for the first time the consequences of a cannibal-dominated era prior to Big Bang Nucleosynthesis for structure formation on small scales. We find that an early cannibal-dominated era imprints a characteristic peak on the dark matter power spectrum, with scale and amplitude directly determined by the mass, lifetime, and number-changing interaction strength of the cannibal field. This enhancement to the small-scale matter power spectrum will generate early-forming dark matter microhalos, and we provide a detailed and transparent map between the properties of the cannibal species and the characteristic mass and formation time of these structures. These relations demonstrate how the internal workings of a hidden sector leave a potentially observable imprint on the matter power spectrum even if dark matter has no direct couplings to the Standard Model.