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Anti-matter black-hole, matter black hole, different?

  1. Nov 7, 2009 #1
    Are a anti-matter black-hole, matter black hole, different?

    Thank you for any help.
    Last edited: Nov 7, 2009
  2. jcsd
  3. Nov 7, 2009 #2


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    Presumably an anti-matter black hole would be created by the collapse of an anti-matter star, or whatever process it is which generates galactic black holes, but with anti-matter. Since black holes are characterized only by their mass, charge, and spin, we can conclude things about any observable differences. Namely, mass will be equal, charge opposite, and spin the same (I think). Since charge is opposite, but still presumably within the realm a matter BH could have, the two would be indistinguishable.
  4. Nov 8, 2009 #3
    That's correct. This is due to the fact that there's no force associated with baryon or lepton numbers. In a sense you could distinguish them by checking what their baryon and lepton numbers were, but there's no measurement you can do that would tell you that.
  5. Nov 8, 2009 #4
    So what would happen if anti matter BH draws matter to itself. It would loose mass?
  6. Nov 8, 2009 #5


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    No, it would gain mass. It doesn't matter whether it's matter of anti-matter as far as the black hole is concerned, they both have positive mass.
  7. Nov 8, 2009 #6
    Something like energy released from matter - anti matter annihilation couldn't escape?
  8. Nov 8, 2009 #7


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    Correct. Once you're past the event horizon, no signal can escape. This includes photons, pions, or any other particles created by particle/ anti-particle annihilations.
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