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Topology and the Cosmic Microwave Background

Добавлено: Ср апр 04, 2007 7:58
J.F.
Topology and the Cosmic Microwave Background
http://meghnad.iucaa.ernet.in/~himan/codes/pr.pdf
Janna Levin
DAMTP, CMS, Cambridge University,
Wilberforce Rd, Cambridge CB3 0WA, U.K.
j.levin@damtp.cam.ac.uk
and
Theoretical Physics Group, Imperial College, London
Nature abhors an infnity. The limits of general relativity are often signaled by infnities: infinite curvature as in the center of a black hole, the infinite energy of the singular big bang. We might be inclined to add an infinite universe to the list of intolerable infnities. Theories that move beyond general relativity naturally treat space as fnite. In this review we discuss the mathematics of finite spaces and our aspirations to observe the fnite extent of the universe in the cosmic background radiation.
http://www.amazon.com/o/ASIN/0753813769 ... MS8B5SY382
How the Universe Got Its Spots (Paperback)
by Janna Levin (Author)


Editorial Reviews

Book Description
Conventional wisdom says the universe is infinite. But could it be finite, merely giving the illusion of infinity? Modern science is beginning to drag this abstract issue into the realm of the real, the tangible and the observable. HOW THE UNIVERSE GOT ITS SPOTS looks at how science is coming up sharp against the mind-boggling idea that the universe may be finite. Through a decade of observation and thought-experiment, we have started to chart out the universe in which we live, just as we have mapped the oceans and continents of our planet. Through a kind of cosmic archaeology and without leaving Earth, we can look at the pattern of hot spots left over from the big bang and begin to trace the 'shape of space'. Beautifully written in a colloquial style by a world authority, Janna Levin explores our aspirations to observe our universe and contemplate our deep connection with it.

About the Author
Janna Levin is PPARC Advanced Fellow in the Department of Applied Mathematics and Theoretical Physics at the University of Cambridge. She has published widely in academic journals and her work has been featured in science magazines and newspapers worldwide.

Добавлено: Чт июн 05, 2008 19:33
J.F.
Well-proportioned universes
suppress CMB quadrupole
http://arxiv.org/PS_cache/astro-ph/pdf/ ... 2312v2.pdf
Jeffrey Weeks, Jean-Pierre Luminet,
Alain Riazuelo, Roland Lehoucq
February 2, 2008
We illustrate this principle in detail for the special
cases of rectangular 3-tori and spherical spaces. We conclude
that well-proportioned spaces make the best candidates for a topological
explanation of the low CMB quadrupole observed by COBE and
WMAP.

NEW RESTRICTIONS ON SPATIAL TOPOLOGY OF THE UNIVERSE
FROM MICROWAVE BACKGROUND TEMPERATURE FLUCTUATIONS
http://xxx.tau.ac.il/PS_cache/gr-qc/pdf ... 5019v1.pdf
A. A. Starobinsky
L. D. Landau Institute for Theoretical Physics, Russian Academy of Sciences
117334, Moscow, Russia
Submitted to JETP Letters 15 April 1993
If the Universe has the topology of a 3-torus (T3), then it follows from recent data on
large-scale temperature fluctuations T/T of the cosmic microwave background that either
the minimal size of the torus is at least of the order of the present cosmological horizon,
or the large-scale T/T pattern should have a symmetry plane (in case of the effective T1
topology) or a symmetry axis (in case of the effective T2 topology), the latter possibility
being probably excluded by the data