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

Abstract

Mixed cold-hot dark matter cosmological models (CHDM) with $\hat{I}{\text{c◯}}_{tot}=1$, 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 $\hat{I}{\text{c◯}}_{\hat{I}}½$ (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 $Ly-\hat{I}\pm$ clouds.

5 pages, LaTeX file, 1 figure. Postscript version of paper is at ftp://ftp.cita.utoronto.ca/ftp/cita/dmitry/mdm_nv_text.ps, and figure is at ftp://ftp.cita.utoronto.ca/ftp/cita/dmitry/mdm_nv_fig.ps