Nb. this is astro-ph/0310233. However it looks now as if it has been
accepted by PRL.
am
----- Forwarded message from physnews(a)aip.org -----
Date: Wed, 12 May 2004 14:50:16 -0400
From: physnews(a)aip.org
PHYSICS NEWS UPDATE
The American Institute of Physics Bulletin of Physics News
Number 685 May 12, 2004 by Phillip F. Schewe, Ben Stein
OUR UNIVERSE HAS A TOPOLOGY SCALE OF AT LEAST 24 Gpc, or about 75
billion light years, according to a new analysis of data from the
Wilkinson Microwave Anisotropy Probe (WMAP). What does this mean?
Well, because of conceivable hall-of-mirrors effects of spacetime,
the universe might be finite in size but give us mortals the
illusion that it is infinite. For example, the cosmos might be
tiled with some repeating shape, around which light rays might wrap
themselves over and over ("wrap" in the sense that, as in video
games, something might disappear off the left side of the screen and
reappear on the right side). A new study by scientists from
Princeton, Montana State, and Case Western looks for signs of such
"wrapped " light in the form of pairs of circles, in opposite
directions in the sky, with similar patterns in the temperature of
the cosmic microwave background. If the universe were finite and
actually smaller than the distance to the "surface of last
scattering" (a distance that essentially constitutes the edge of the
"visible universe," and the place in deep space whence comes the
cosmic microwaves), then multiple imaging should show up in the
microwave background. But no such correspondences appeared in the
analysis. The researchers are able to turn the lack of recurring
patterns into the form of a lower limit on the scale of cosmic
topology, equal to 24 billion parsecs, a factor of 10 larger than
previous observational bounds. (Cornish, Spergel, Starkman,
Komatsu, Physical Review Letters, upcoming article; contact Neil
Cornish, 406-994-7986, cornish(a)physics.montana.edu)
[...]
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