The Shape of Space from Einstein to WMAP data
Abstract
In this talk I review recent advances in cosmic topology since it has entered a new era of experimental tests. High redshift surveys of astronomical sources and accurate maps of the Cosmic Microwave Background radiation (CMB) are beginning to hint at the shape of the universe, or at least to limit the wide range of possibilities. Among those possibilites are surprising ``wrap around'' universe models in which space, whatever its curvature, may be smaller than the observable universe and generate topological lensing effects on a detectable cosmic scale. In particular, the recent analysis of CMB data provided by the WMAP satellite suggest a finite universe with the topology of the Poincaré dodecahedral spherical space. Such a model of a ``small universe'', the volume of which would represent only about 80% the volume of the observable universe, offers an observational signature in the form of a predictable topological lens effect on one hand, and rises new issues on the early universe physics on the other hand.
 Publication:

A Century of Relativity Physics: ERE 2005
 Pub Date:
 June 2006
 DOI:
 10.1063/1.2218171
 Bibcode:
 2006AIPC..841..115L
 Keywords:

 98.80.Jk;
 98.70.Vc;
 Mathematical and relativistic aspects of cosmology;
 Background radiations