A&A 456, 13-21 (2006)
DOI: 10.1051/0004-6361:20054668
Non-Friedmann cosmology for the Local Universe, significance of the universal Hubble constant, and short-distance indicators of dark energy
A. D. Chernin1, 2, 3, P. Teerikorpi1 and Yu. V. Baryshev4, 51 Tuorla Observatory, University of Turku, 21500 Piikkiö, Finland
2 Sternberg Astronomical Institute, Moscow University, 119899, Moscow, Russia
3 Division of Astronomy, University of Oulu, 90014, Finland
4 Institute of Astronomy, St.Petersburg State University, Staryj Peterhoff, 198504, St. Petersburg, Russia
5 Isaac Newton Institute of Chile, Saint-Petersburg Branch, Russia
(Received 8 December 2005 / Accepted 19 April 2006 )
Abstract
Based on the increasing evidence of the cosmological
relevance of the local Hubble flow, we consider a simple analytical
cosmological model for the Local Universe. This is a non-Friedmann
model with a non-uniform static space-time. The major dynamical
factor controlling the local expansion is the
antigravity produced by the omnipresent and permanent dark
energy of the cosmic vacuum (or the cosmological constant). The
antigravity dominates at larger distances than 1-2 Mpc from the
center of the Local group. The model gives a natural
explanation of the two key quantitative characteristics of the
local expansion flow, which are the local Hubble constant and the
velocity dispersion of the flow. The observed kinematical
similarity of the local and global flows of expansion is
clarified by the model. We analytically demonstrate the
efficiency of the vacuum cooling mechanism
that allows one to see the Hubble law this close to the Local group.
The "universal Hubble constant"
(
60 km s-1 Mpc-1),
depending only on the vacuum density, has special
significance locally and globally.
The model makes a number of verifiable predictions.
It also unexpectedly shows that
the dwarf galaxies of the local flow with the shortest distances
and lowest redshifts may be the most sensitive indicators of
dark energy in our neighborhood.
Key words: cosmology: dark matter -- cosmology: cosmological parameters -- galaxies: Local Group
© ESO 2006

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