Late universe dynamics with scale-independent linear couplings in the dark sector

Simple item page
dc.creatorQuercellini, Claudia
dc.creatorBruni, Marco
dc.creatorBalbi, Amedeo
dc.creatorPietrobon, Davide
dc.date2008-03-13
dc.date2008-07-21
dc.date.accessioned2026-07-07T12:44:31Z
dc.date.available2026-07-07T12:44:31Z
dc.descriptionWe explore the dynamics of cosmological models with two coupled dark components with energy densities $ρ_A$ and $ρ_B$. We assume that the coupling is of the form $Q=Hq(ρ_A,ρ_B)$, so that the dynamics of the two components turns out to be scale independent, i.e. does not depend explicitly on the Hubble scalar $H$. With this assumption, we focus on the general linear coupling $q=q_o+q_Aρ_A+q_Bρ_B$, which may be seen as arising from any $q(ρ_A,ρ_B)$ at late time and leads in general to an effective cosmological constant. In the second part of the paper we consider observational constraints on the form of the coupling from SN Ia data, assuming that one of the components is cold dark matter. We find that the constant part of the coupling function is unconstrained by SN Ia data and, among typical linear coupling functions, the one proportional to the dark energy density $ρ_{A}$ is preferred in the strong coupling regime, $|q_{A}|>1$. While phantom models favor a positive coupling function, in non-phantom models, not only a negative coupling function is allowed, but the uncoupled sub-case falls at the border of the likelihood.
dc.description12 pages, 5 figures, considerable changes to the text
dc.identifierhttps://arxiv.org/abs/0803.1976
dc.identifierhttp://arxiv.org/abs/0803.1976
dc.identifierPhys.Rev.D78:063527,2008
dc.identifierdoi:10.1103/PhysRevD.78.063527
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/220798
dc.subjectAstrophysics
dc.subjectGeneral Relativity and Quantum Cosmology
dc.titleLate universe dynamics with scale-independent linear couplings in the dark sector
dc.typetext

Files

Collections

arXiv