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Vacuum metastability event

  1. Jun 29, 2009 #1
    I'm having trouble understanding this part of a wikipedia article on false vacuum


    In their paper, Coleman and de Luccia noted:
    The possibility that we are living in a false vacuum has never been a cheering one to contemplate. Vacuum decay is the ultimate ecological catastrophe; in the new vacuum there are new constants of nature; after vacuum decay, not only is life as we know it impossible, so is chemistry as we know it. However, one could always draw stoic comfort from the possibility that perhaps in the course of time the new vacuum would sustain, if not life as we know it, at least some structures capable of knowing joy. This possibility has now been eliminated.

    I don't understand the last part. Are they saying that no large scale matter structures can exist outside of a false vacuum? How would they know? I looked at the article at

    http://prola.aps.org/pdf/PRD/v21/i12/p3305_1 [Broken]

    and I don't see an explanation of that conclusion. I can email the article to anybody who doesn't have access
     
    Last edited by a moderator: May 4, 2017
  2. jcsd
  3. Jun 30, 2009 #2

    Chalnoth

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    Here's a public version of the article: http://www.slac.stanford.edu/pubs/slacpubs/2000/slac-pub-2463.html [Broken]

    It looks like they are assuming that the universe in which we live has zero cosmological constant, which would, in turn, make the vacuum-collapsed bubble into anti de Sitter space, which causes it to be dynamically unstable. Their calculations may not be valid if the current universe has a small but positive cosmological constant.
     
    Last edited by a moderator: May 4, 2017
  4. Jun 30, 2009 #3
    And what would the interface between the two states look like? Would there not need to be a higher-energy maximum there, which would be unstable? Or are they saying the entire universe might flip to the metastable state? If so, it seems there would need to be a finite non-zero time during which different parts of the universe had the different states. Also, if that's what they are saying, then even not considering the transition period, that would change the total energy of the universe. If I understand what they are saying, then I suspect it is wrong even if there isn't a cosmological constant.
     
  5. Jun 30, 2009 #4

    Chalnoth

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    Well, you might want to read their paper a bit. At least the introduction. It explains rather clearly the picture of what is going on. The proposal is that there is a quantum tunneling event somewhere in the universe that hops to the true vacuum, which causes an expanding bubble of true vacuum to appear.
     
  6. Jul 1, 2009 #5

    Chronos

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    I dont care for that proposition. I perceive no issues with the observable universe that require exquisite mathematical beauty. The most appealing theories of how the universe behaves tend to be ugly and complicated.
     
    Last edited: Jul 1, 2009
  7. Jul 1, 2009 #6

    Chalnoth

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    That depends upon what you mean. In a sense, though, the search for mathematical beauty in physical law is just another way of looking at Occam's Razor. Typically the consequences of the simple laws, of course, are ugly and complicated. But the laws themselves can often be stated simply, and the search for ways to state said laws even more simply has often led to great advances in theoretical physics.
     
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