Parameter constraints for flat cosmologies from cosmic microwave background and 2dFGRS power spectra

• DOI: 10.1046/j.1365-8711.2002.06001.x
• Publication Date: 2003-03-12T14:26:30Z
• Authors: W. J. Percival; W. Sutherland; J. A. Peacock; C. M. Baugh; J. Bland-Hawthorn; T. Bridges; R. Cannon; S. Cole; M. Colless; C. Collins; W. Couch; G. Dalton; R. De Propris; S. P. Driver; G. Efstathiou; R. S. Ellis; C. S. Frenk; K. Glazebrook; C. Jackson; O. Lahav; I. Lewis; S. Lumsden; S. Maddox; S. Moody; P. Norberg; B. A. Peterson; K. Taylor
• Keywords: Cosmological constant; CMB cold spot; Cosmic background radiation

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