Constraining Dark Matter-Dark Radiation interactions with CMB, BAO, and Lyman-α
Rattachement africain : it, de, is. Niveau de preuve : code pays fourni par la source.
Le résumé fourni par la source
Several interesting Dark Matter (DM) models invoke a dark sector leading to two types of relic particles, possibly interacting with each other: non-relativistic DM, and relativistic Dark Radiation (DR). These models have interesting consequences for cosmological observables, and could in principle solve problems like the small-scale cold DM crisis, Hubble tension, and/or low $\sigma_8$ value. Their cosmological behaviour is captured by the ETHOS parametrisation, which includes a DR-DM scattering rate scaling like a power-law of the temperature, $T^n$. Scenarios with $n=0$, $2$, or $4$ can easily be realised in concrete dark sector set-ups. Here we update constraints on these three scenarios using recent CMB, BAO, and high-resolution Lyman-$\alpha$ data. We introduce a new Lyman-$\alpha$ likelihood that is applicable to a wide range of cosmological models with a suppression of the matter power spectrum on small scales. For $n=2$ and $4$, we find that Lyman-$\alpha$ data strengthen the CMB+BAO bounds on the DM-DR interaction rate by many orders of magnitude. However, models offering a possible solution to the missing satellite problem are still compatible with our new bounds. For $n=0$, high-resolution Lyman-$\alpha$ data bring no stronger constraints on the interaction rate than CMB+BAO data, except for extremely small values of the DR density. Using CMB+BAO data and a theory-motivated prior on the minimal density of DR, we find that the $n=0$ model can reduce the Hubble tension from $4.1\sigma$ to $2.7\sigma$, while simultaneously accommodating smaller values of the $\sigma_8$ and $S_8$ parameters hinted by cosmic shear data.
Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.
Le contrôle bibliographique ouvert
Où se fait cette recherche
-
Istituto Nazionale di Fisica Nucleare pays non établi dans la noticeStructure de recherche
-
RWTH Aachen University Institute for Theoretical Particle Physics and Cosmology (TTK) pays non établi dans la noticeUniversité ou école supérieure
-
University of Bologna pays non établi dans la noticeUniversité ou école supérieure
-
Scuola Internazionale Superiore di Studi Avanzati pays non établi dans la noticeUniversité ou école supérieure
-
Institute for Fundamental Physics of the Universe IFPU pays non établi dans la noticeStructure de recherche
-
University of Iceland Science Institute pays non établi dans la noticeUniversité ou école supérieure
-
Trieste Astronomical Observatory pays non établi dans la noticeStructure de recherche
-
Dipartimento di Fisica e Astronomia pays non établi dans la noticeInstitution
-
INFN pays non établi dans la noticeInstitution
-
SISSA pays non établi dans la noticeInstitution
-
INAF pays non établi dans la noticeInstitution
Istituto Nazionale di Fisica Nucleare, Institute for Theoretical Particle Physics and Cosmology (TTK) — RWTH Aachen University et University of Bologna, avec 8 autres affiliations.
Une affiliation ne permet pas de déduire la nationalité d’un auteur.