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Chaotic Eternal Inflation vs. False Vacuum Eternal Inflation

  1. Sep 15, 2009 #1
    I hope someone can help me understand some inflation principles.

    In Alan Guth's popular book: The Inflationary Universe, he presents a schematic of a false vacuum universe decaying into pocket universes. The false vacuum expands exponentially as the pocket universes are continuously generated. The process continues into the future forever.

    Now in the chaotic eternal inflation theory originally proposed by Linde, a scalar field potential (of the form V = m * Phi ^2 / 2) exists and inflation happens as the scalar field, Phi, rolls down the potential energy curve.

    As Guth points out in his 2007 paper, in one Hubble time during inflation, the volume will increase by a factor of e^3 = 20. As the scalar field is rolling, quantum fluctuations may make the positive change in Phi greater than the classic decrease in Phi. So if the chance of this happening is > 1/20, then chaotic inflation is eternal.

    This leads to my question. The false vacuum / pocket universe model seems to have a bunch of separate space time regions. But the choatic eternal inflation seems to be separate regions in the same space time. Is this correct?
  2. jcsd
  3. Sep 15, 2009 #2
    My understanding is thatIn standard inflation, inflationary expansion occurred while the universe was in a false vacuum state, halting when the universe decayed to a true vacuum state becoming a general and inclusive phenomenon with homogeneity throughout, yielding a single expanding universe which is “our general reality” wherein the laws of physics are consistent throughout. The bubble universe model proposes that different regions of this inflationary universe (termed a multiverse) decayed to a true vacuum state at different times, with decaying regions corresponding to “sub”- universes not in causal contact with each other and resulting in different physical laws in different regions which are then subject to “selection” which determines each region’s components based upon (dependent on) the survivability of its quantum components within that region. The end result will be a finite number of universes with physical laws consistent within each region of spacetime. Variants of the bubble universe model postulate multiple false vacuum states, which result in lower-energy false-vacuum “progeny” universes spawned, which in turn produce true vacuum state progeny universes within themselves.
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