Crunchy Cat said:
Sure thing. Dr. Andrei Linde (Professor of Physics @ Stanford University) gave a public lecture about this in March 2003. I am sure he is still active in this area and I would suggest reaching out to him for further info.
"Dr. Andrei Linde of Stanford University, a leading inflation theorist, cautioned that the principle should be invoked with care, but that it seemed sensible to assess all cosmic parameters, all elements brought to bear in support of theories, with one view in mind, namely, "what allows us to be here."
"Only the anthropic principle plus inflation will explain the universe as we see it," Linde concluded.
Both Linde and Guth of MIT have taken another romantic plunge with the idea of "eternal inflation." If an explosive event like the Big Bang, followed immediately by a brief phase of rapid cosmic expansion, happened once, they posit that it could happen an infinite number of times, and may well have.
Conceiving of an inflation that cannot reproduce bubbles of new universes many times, Guth said, seemed "as implausible as discovering a species of rabbits incapable of reproduction." He paused. "So universes reproduce like rabbits."
From the front row, Dr. Rocky Kolb of the University of Chicago piped up, "You mean, pull it out of the hat."
"OK, I'll look for a different analogy some other time," Guth responded.
If there are parallel universes elsewhere, each would have started with its own big bang, grown from a separate inflationary bubble and probably acquired entirely different laws of physics. Ours may not be a typical universe. Instead of the four dimensions of space-time in this universe, Linde suggested, other universes could have as many as 11 dimensions; some could be dimension-challenged, with only 3. Some universes could be stillborn or unstable and short-lived, thus lacking the time to evolve stars and planets where life might emerge. It could be, invoking anthropic reasoning, that a universe must have, say, a cosmological constant of precisely the right value and properties to support intelligent life.
The romantics may have outdone themselves with their eternal inflation and a multiverse instead of a universe. Even if scientists established sound reasons for their existence, parallel universes would be discrete and widely separated entities, beyond communication with each other.
No one in this universe, cosmologists said, would be able to gain any direct knowledge of other universes, though in time the theorists might make a persuasive case for their existence. Human beings would then have discovered the ultimate limit to their knowing what is out there. They might find solace, though, if there is anything to the anthropic principle, in thinking that theirs is a defining presence in the one universe they know and are trying to comprehend."
http://www.ishipress.com/cosmos.htm
Dr. Andrei Linde is a proponent of the inflationary universe theory: inflate-defate-inflate-deflate: expand-contract-expand-contract. But as the reporter states above, "the romantics may have outdone themselves" on this one: multi-universe theory like "rabbits reproducing...OK I'll look for a different analogy."
I can conceive that there are multiple dimensions, but what he's putting forward here, without any explanations as to how (cause-effect, means of way) is kind've a crack-pot. He's throwing out many different possible theories without any support or explanations.
However, also:
"By analyzing the bumps in the cosmic microwaves, which according to inflation are the result of microscopic fluctuations in the mysterious force field that drove inflation, along with other data, scientists have ruled out one simple version of inflation that is often seen in textbooks. Other versions, he added, fit the data quite well. The data are good enough to rule out whole classes of inflationary theories. That is a boon for particle physicists, who want to know what laws governed the universe at the beginning of time."
http://www.arn.org/docs2/news/bigbangconfirmation021302.htm