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Nov25-11, 02:22 PM
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marcus's Avatar
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I glanced at this thread just briefly, not enough to join discussion. But want to make a comment.
Skydivephil makes a lot of good points in his cosmology forum posts but I think he is only partially right in something here.

He says "multiverse is a logical consequence of inflation". That's not true for inflation itself, but for a lame idea of an inflation mechanism.

Inflation happens normally in Loop cosmology without assuming any "quantum fluctuations" or other leaps of faith that are then hard to turn off or get rid of.

In that context there is no reason for inflation to be eternal or chaotic or happen repeatedly. It is just something that happens (under fairly mild assumptions) in connection with a particular quantum relativistic collapse and rebound.

It can be treated as a one-time process that is part of a one-time bounce. No need to go beyond that into grandiose realms of untestable fantasy. In Loop context, adequate one-time inflation is mundane and robust. The physics of the bounce itself sets it up and triggers it.

It's when you don't have a simple straightforward explanation for adequate inflation at the start of expansion, that you have to invoke leap-of-faith explanations that then will not stop producing universes. This then becomes an embarrassment, as in the Sorcerer's Apprentice story where the magic keeps on fetching water far beyond what is wanted or relevant to the problem.