Parameter constraints for flat cosmologies from CMB and 2dFGRS power spectra

Details Parameter constraints for flat cosmologies from CMB and 2dFGRS power spectra Parameter constraints for flat cosmologies from CMB and 2dFGRS power spectra

2002-06-14

arxiv.org/abs/astro-ph/0206256v2

Mon.Not.Roy.Astron.Soc.337:1068,2002

Astronomy and Astrophysics

Astrophysics

14 pages, 7 figures, minor revision, accepted for publication in MNRAS

Scientific paper

10.1046/j.1365-8711.2002.06001.x

We constrain flat cosmological models with a joint likelihood analysis of a new compilation of data from the cosmic microwave background (CMB) and from the 2dF Galaxy Redshift Survey (2dFGRS). Fitting the CMB alone yields a known degeneracy between the Hubble constant h and the matter density Omega_m, which arises mainly from preserving the location of the peaks in the angular power spectrum. This `horizon-angle degeneracy' is considered in some detail and shown to follow a simple relation Omega_m h^{3.4} = constant. Adding the 2dFGRS power spectrum constrains Omega_m h and breaks the degeneracy. If tensor anisotropies are assumed to be negligible, we obtain values for the Hubble constant h=0.665 +/- 0.047, the matter density Omega_m=0.313 +/- 0.055, and the physical CDM and baryon densities Omega_c h^2 = 0.115 +/- 0.009, Omega_b h^2 = 0.022 +/- 0.002 (standard rms errors). Including a possible tensor component causes very little change to these figures; we set a upper limit to the tensor-to-scalar ratio of r<0.7 at 95% confidence. We then show how these data can be used to constrain the equation of state of the vacuum, and find w<-0.52 at 95% confidence. The preferred cosmological model is thus very well specified, and we discuss the precision with which future CMB data can be predicted, given the model assumptions. The 2dFGRS power-spectrum data and covariance matrix, and the CMB data compilation used here, are available from http://www.roe.ac.uk/~wjp/

Affiliated with

Also associated with

No associations

Rating

Parameter constraints for flat cosmologies from CMB and 2dFGRS power spectra does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Parameter constraints for flat cosmologies from CMB and 2dFGRS power spectra, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Parameter constraints for flat cosmologies from CMB and 2dFGRS power spectra will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-258119