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What do y'all think about the ekpyrotic cosmology? (pdf)

Background for lurkers:

Agreement between the theoretical idea of inflation and experiment is convincing. However, model building is still difficult and seems to require several assumptions and fine-tuning of parameters. This leads to the question of whether there are serious competitors for inflation, for example, in M-theory. This would be desirable since some basic arguments state that de Sitter space-times, which describe an exponentially growing universe, are difficult to implement in supergravity and superstring theories. As Fernando Quevedo of Cambridge discussed, there is a nice way to build inflationary models into brane-world models in string theory in such a way as to trigger the graceful exit from inflation. This leads to a hybrid inflationary scenario being realized in brane-world models. A more radical approach to explaining the flatness and horizon problems - one that really competes with inflation - was introduced by Burt Ovrut from the University of Pennsylvania. Taking its name from a Greek word meaning conflagration, the ekpyrotic universe theory explains the rapid expansion of the early universe as arising from the collision of branes. Through such a collision, a huge amount of energy is almost uniformly and homogeneously deposited on our universe. Despite offering a fascinating and challenging alternative to standard inflation, many aspects of the ekpyrotic universe need further investigation This article contains an interview with Burt Ovrut: The Ekpyrotic Universe - A Collision Before the Big Bang?

A brand new theory about the creation of the universe emerged recently from cosmologists and particle physicists at Princeton University, the University of Pennsylvania and Cambridge, England. The new theory is called the Ekpyrotic Universe, from a Greek word meaning "conflagration" used to describe the universe's creation from a huge fireball that cooled down. Periodically, the Greeks thought, the process could repeat itself.

The new Ekpyrotic theory has grown out of string and super string theory that says there have to be eleven dimensions. We live in the first four of 3-dimensional matter plus time. The 5th dimension is the one in which, the new theory goes, a cataclysmic event took place that ended up creating the universe we are now living in. Dimensions 6 through 11 are like scaffolding behind the scenes upon which our 3-dimensional theater plays out. Dimensions 6 through 11 are also tiny and curled up into little "strings" which are too small to see, but without them the universe could not exist.

String theory says that dimensions 1 through 4 "float," so to speak, in the 5th dimension. The new theory suggests that not only is our universe floating in the 5th dimension, but the 5th dimension can have waves in it just like the ocean. Further, one or more of those 5th dimensional waves can become a soliton - meaning, a wave can form that keeps on going as a wave and does not collapse. If such a 5th dimensional soliton wave should come in contact with a 4-dimensional universe such as ours, what would happen? That's what these cosmologists and mathematicians have been working on. Rather than calling this a universe and the soliton wave a wave, theorists today now refer to large scale mathematical features in different dimensions as "branes." The term originated from discussions about "membranes" between or in different dimensions.

Recently in a meeting at the Space Telescope Science Institute in Maryland, this new theory about the creation of our universe from a 5th dimensional brane slamming into a 4-dimensional matter universe was presented by Princeton astrophysicist, Paul Steinhardt. He worked out the mathematical details over the last year and a half with Princeton graduate student, Justin Khoury; Cambridge, England physicist Neil Turok; and University of Pennsylvania particle physicist and mathematician, Burt Ovrut.

I visited Dr. Ovrut at his Penn Physics Department office this week to talk about this new theory of universe creation from a collision between different dimensions. He began by describing his concept of the 5th dimension.

Phaedrus: this is a bit like your suggestion of the crest of a wave (please read the last link.)