Cosmological parameters from velocities, cosmic microwave background and supernovae
Abstract
We compare and combine likelihood functions of the cosmological parameters Ω_{m}, h and σ_{8}, from peculiar velocities, cosmic microwave background (CMB) and type Ia supernovae. These three data sets directly probe the mass in the Universe, without the need to relate the galaxy distribution to the underlying mass via a `biasing' relation. We include the recent results from the CMB experiments BOOMERANG and MAXIMA1. Our analysis assumes a flat Λ cold dark matter (ΛCDM) cosmology with a scaleinvariant adiabatic initial power spectrum and baryonic fraction as inferred from bigbang nucleosynthesis. We find that all three data sets agree well, overlapping significantly at the 2σ level. This therefore justifies a joint analysis, in which we find a joint bestfitting point and 95per cent confidence limits of Ω_{m}= 0.28 (0.17,0.39), h=0.74 (0.64,0.86) and σ_{8}=1.17 (0.98,1.37). In terms of the natural parameter combinations for these data σ_{8}Ω^{0.6}_{m}=0.54 (0.40,0.73), Ω_{m}h =0.21 (0.16,0.27). Also for the bestfitting point, Q_{rmsps}=19.7 μK and the age of the Universe is 13.2Gyr.
 Publication:

Monthly Notices of the Royal Astronomical Society
 Pub Date:
 February 2001
 DOI:
 10.1046/j.13658711.2001.04009.x
 arXiv:
 arXiv:astroph/0006170
 Bibcode:
 2001MNRAS.321..333B
 Keywords:

 methods: statistical;
 cosmic microwave background;
 cosmological parameters;
 cosmology: observations;
 cosmology: theory;
 largescale structure of Universe;
 Astrophysics
 EPrint:
 8 pages, 5 figures. Submitted to MNRAS