Wednesday, October 13, 2010

Big bounce cosmos makes inflation a sure thing - space - 13 October 2010 - New Scientist

Big bounce cosmos makes inflation a sure thing: Enter loop quantum gravity, devised by Abhay Ashtekar of Pennsylvannia State University (PSU) in University Park and colleagues to reconcile general relativity with quantum mechanics. When Ashtekar's team created cosmological models inspired by LQG in 2006, these suggested the universe emerged from the remnants of an earlier universe that was crunched down to a tiny volume by gravity, not from the big bang (see diagram).

Now, together with David Sloan, also at PSU, Ashtekar has calculated the probability of inflation occurring after this big bounce. "We find that the probability of inflation is incredibly close to 1," he says.

Earlier simulations showed that the big bounce creates a repulsive force and so is always followed by a period of rapid expansion that is even faster than inflation. Dubbed superinflation, this episode doesn't last long enough to replace inflation. But the pair's latest calculations show that it has a profound effect on space-time, such that no matter what the initial properties are in the early universe, superinflation "funnels" all the possible ways in which space-time can evolve towards one in which inflation is a near certainty

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