Dear Yanniru,

An alternative to both the Big Bang and the Big Rip is the Cyclic universe that derives from Witten's 11-d M superstring theory. A very readable sumary just came out on the Cornell archives today.

It compares the cyclic model to the inflation model and claims they are indistinguishable unles density perturbations are preserved thru the cyclic bounce, in which case the spectrum of density fluctuations will differ. So WMAP measurements might be definitive. The paper however concludes that the cyclic model is based on a theory that is not yet complete.

Wanda

Here is the abstract and its link:

A Briefing on the Ekpyrotic/Cyclic Universe
Authors: Justin Khoury (Columbia Univ.)
Comments: 8 pages, 1 figure. Invited talk at the 6th RESCEU Symposium, Nov. 2003, Tokyo, Japan

This is a short overview of the ekpyrotic/cyclic model of the universe, an alternative to the standard big bang inflationary paradigm.
Full-text: PostScript, PDF, or Other formats

http://arxiv.org/abs/astro-ph/0401579

• Moreon th Big Rip - yanniru - March 22, 2004 - 16:33 UTC