March 2003 - Cosmo-torun - cosmo.torun.pl

"projective sphere" (fwd)
by boud 01 Apr '03

01 Apr '03

hi, i received this from a friend. The projective sphere is the 2-sphere S^2 where each point is identified with its opposite point. So the fundamental polygon is a hemisphere. Geodesics only intersect once in the projective sphere. > Hi Boud, > what an irony, but I am looking for your help with Polish !!! > Could you or your collaborators on topology in Torun > enlighten me with Polish term for "projective sphere" ? > Thanks in advance, Can anyone help? boud

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topology - WMAP - urgent
by boud 19 Mar '03

19 Mar '03

Witam, Micha³, Bartek, anyone else interested. Now that there's some big time media coverage, anyone interested in working together on this? IMHO it's urgent to do the analysis ourselves. I haven't fully understand Marek's comments, but I think he's just playing safe ;) - no harm there. Anyone who sees signs that our North/South American and or European colleagues have done something concrete on this, please say and point to the URL! Boud amr wrote: > Artyku³ o odkryciu ("odkryciu" ?) Tegmarka: > http://www.gazeta.pl/nauka/1,34148,1376101.html > Krytyka Marka Demiañskiego: > http://www1.gazeta.pl/nauka/1,34148,1376526.html ---------- Forwarded message ---------- > Date: Wed, 19 Mar 2003 12:57:53 +0100 (MET) > From: Programme National de Cosmologie <pnc at iap.fr> > To: diffusion PNC <pnc at iap.fr> > Subject: divers ... --------------------------------------------------------------------------- PNC PNC PNC http://www.iap.fr/pnc/ PNC PNC PNC PNC --------------------------------------------------------------------------- 4. Extraits d'un article du New-York Times du 11 mars 2003 "Universe as Doughnut: New Data, New Debate" The New York Times March 11, 2003 Universe as Doughnut: New Data, New Debate By DENNIS OVERBYE Long ago in the dawn of the computer age, college students often whiled away the nights playing a computer game called Spacewar. It consisted of two rocket ships attempting to blast each other out of the sky with torpedoes while trying to avoid falling into a star at the center of the screen. Although cartoonish in appearance, the game was amazingly faithful to the laws of physics, complete with a gravitational field that affected both the torpedoes and the rockets. Only one feature seemed outlandish: a ship that drifted off the edge of the screen would reappear on the opposite side. Real space couldn't work that way. Or could it? Imagine that the Spacewar screen is wrapped around to form a cylinder or a section of a doughnut so that the two edges meet. That is the picture of space, some cosmologists say, that has been suggested by a new detailed map of the early universe. Their analysis of this map has now provided a series of hints though only hints that the universe may have a more complicated shape than astronomers presumed. ... This mirror game is not limited to cubes and doughnuts. Over the years mathematicians, particularly Dr. William Paul Thurston, now at the University of California at Davis, and Dr. Jeffrey Weeks, an independent mathematician, have speculated about universes composed of various polyhedrons glued together in various ways. In 1996 the French astronomer Dr. Jean-Pierre Luminet of the Paris Observatory and his colleagues Dr. Roland Lehoucq and Dr. Marc Lachieze-Rey, both of the Center for Astrophysical Studies in Saclay, France, developed a method called "cosmic crystallography," using galaxy statistics to detect and diagnose the repeating periodic patterns that would be created in the sky by light going around and around in differently shaped universe. Finite or Infinite? Problems Are Posed For Favored Theory ...

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astro-ph/0302496 - T^1 model in WMAP data? - compare astro-ph/0007140
by Boud Roukema 13 Mar '03

13 Mar '03

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