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Naked singularities

  1. Apr 7, 2008 #1
    I have a few questions about these. My main question concerns the "theory" that all fundamental particles are actually black holes. If this were the case, at least for an electron, they would be naked singularities because q+a > m.

    1) What are the effects of a naked singularity that make people assume its physically impossible? i.e. I know about closed time loops, but at what range do they occur? Is it only inside of a ring singularity?

    2) I understand qualitatively why a charged black hole can not be naked, because when q>m the repulsion due to the charges is stronger than the attraction of gravity. However for a rotating black hole, is there anything qualitatively that stops it a from exceeding m? From what I understand the centrifugal force due to the rotating ring singularity decreases as a increases so this does not explain it.

    3) Is there any serious research going into viewing fundamental particles as micro (sub-planck really) black holes? Its a really interesting theory and Im wondering if anyone actually views it as a possibility.

    4) On the wikipedia page for micro black hole electrons, they mention that rotating black holes with certain angular momentum will not have hawking radiation. Is this true? Does anyone know the temperature equation for a rotating, charged black hole?
  2. jcsd
  3. Apr 9, 2008 #2
    so as far as 2) is concerned I think I found an answer. One way to explain charged or spinning black holes having a limit in charge or angular momentum is to find when the gravitational force is exceeded by some repulsive force. This explanation is obvious for the charged black hole, and less so for the rotating one. I think I did find the answer though.

    dF_g = G * dM * M / (2*a^2) (force of gravity)
    dF_c = dM * c^2 / a (centrifugal force)

    I found that the ring singularity will become unstable if a > 1/2 * GM/c^2. The factor of 1/2 conflicts with GR, so either this classical approach simply doesnt work or I screwed up somewhere in my calculations.
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