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Collapse of Pauli exclusion principle

  1. Jul 5, 2009 #1
    What happens when a neutron star collapses into a black hole and it's no longer obeying the Pauli exclusion principle? In terms of quantum mechanics? Say it collapses because it gets more massive.
    A "neutron degeneracy pressure" can be calculated, which is what keeps the neutron star from collapsing.
    Since this pressure can be calculated, I suppose people have some idea of what happens when gravitation overwhelms it, in terms of quantum mechanics?
    I'm puzzled because from what I remember, the Pauli exclusion principle comes from adding two quantum states of two particles together, and they're out of phase so they cancel where both positions are the same. It sounds pretty basic and I wonder what happens when this stops working.
  2. jcsd
  3. Jul 5, 2009 #2


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    The questions you are raising point to a fundamental problem of current physics. Specifically when trying to describe what happens inside a black hole, quantum theory and general relativity are in conflict. How to resolve this is an open question.
  4. Jul 6, 2009 #3


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    Electron degeneracy breaks down when there is so much gravity that they become bound to the protons and create neutrons. This is the creation of a neutron star.

    How the Neutron's degeneracy pressure breaks down is unknown to me.
  5. Jul 6, 2009 #4
    If somebody can calculate the pressure resisting the collapse of the Pauli exclusion principle, it seems like they should have some idea of what it's collapsing to. Knowing the pressure seems to indicate knowledge of the process involved.
  6. Jul 6, 2009 #5
    It doesn't have to be a problem because the gravity is able to overcome the degenarcy pressure, i.e. it is able to push the electrons/neutrons to high enough energy states so that they don't occupy the same levels.

    It could also be that at some stage the system makes a transition to an exact supersymmetric state. It has been argued that such transitions could actually happen spontaneously in neutron stars or white dwarfs:



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