Ch. Lineweaver et al., CONSTRAINTS ON H, OMEGA(B) AND LAMBDA(0) FROM COSMIC MICROWAVE BACKGROUND OBSERVATIONS, Astronomy and astrophysics, 322(2), 1997, pp. 365-374
In this paper we compare data to theory. We use a compilation of the m
ost recent cosmic microwave background (CMB) measurements to constrain
Hubble's constant h, the bar)ion fraction nbr and the cosmological co
nstant lambda(0). We fit h-, Omega(b)- and lambda(o)-dependent power s
pectra to the data. The models we consider are flat cold dark matter (
CDM) dominated universes with Bat (n(s) = 1)power spectra, thus the re
sults obtained apply only to these models. CMB observations can exclud
e more than half of the h - Omega(b) parameter space explored. The CMB
data favor low values of Hubble's constant; h approximate to 0.35. Lo
w values of Omega(b) are preferred (Omega(b) similar to 0.03) but the
chi(2) minimum is shallow and we obtain Omega(b) < 0.28. A model with
h approximate to 0.40, Omega(b) approximate to 0.15 and Omega(cdm) app
roximate to 0.85 is permitted by constraints from the CMB data, BBN, c
luster baryon fractions and the shape parameter Gamma derived from the
mass density power spectra of galaxies and clusters. For flat-lambda(
o) models, the CMB data, combined with BBN constraints exclude most of
the h - lambda(o), plane. Models with Omega(o), approximate to 0.3, l
ambda(o), approximate to 0.7 with h approximate to 0.75 are fully cons
istent with the CMB data but are excluded by the strict new q(o) limit
s from supernovae (Perlmutter et al. 1997). A combination of CMB data
goodness-of-fit statistics, BBN and supernovae constraints in the h -
lambda(o), plane, limits Hubble's constant to the interval 0.23 < h <
0.72.