Mixed Cold-Hot Dark Matter Model with several Massive Neutrino Types

Abstract

Mixed cold-hot dark matter cosmological models (CHDM) with $Ω_{tot}=1$, approximately flat initial spectrum of adiabatic perturbations and 1, 2 or 3 types of massive neutrinos are compared and tested using recent observational data. The models with 2 or 3 neutrino types of equal mass permit as the best fit larger values of both the Hubble constant ($H_0\le 60$ for 2 types, $H_0\le 65$ for 3 types) and the total $Ω_ν$ (up to 0.3 for 3 types) than the model with 1 massive type. Also, they have less problems with abundances of early compact objects including $Ly-α$ clouds.