39,561 research outputs found
Gravitational energy as dark energy: Concordance of cosmological tests
We provide preliminary quantitative evidence that a new solution to averaging
the observed inhomogeneous structure of matter in the universe [gr-qc/0702082,
arxiv:0709.0732], may lead to an observationally viable cosmology without
exotic dark energy. We find parameters which simultaneously satisfy three
independent tests: the match to the angular scale of the sound horizon detected
in the cosmic microwave background anisotropy spectrum; the effective comoving
baryon acoustic oscillation scale detected in galaxy clustering statistics; and
type Ia supernova luminosity distances. Independently of the supernova data,
concordance is obtained for a value of the Hubble constant which agrees with
the measurement of the Hubble Key team of Sandage et al [astro-ph/0603647].
Best-fit parameters include a global average Hubble constant H_0 = 61.7
(+1.2/-1.1) km/s/Mpc, a present epoch void volume fraction of f_{v0} = 0.76
(+0.12/-0.09), and an age of the universe of 14.7 (+0.7/-0.5) billion years as
measured by observers in galaxies. The mass ratio of non-baryonic dark matter
to baryonic matter is 3.1 (+2.5/-2.4), computed with a baryon-to-photon ratio
that concords with primordial lithium abundances.Comment: 4 pages, 2 figures; v2 improved statistics, references added, to
appear in ApJ Letter
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