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Collapsars vrs. QM degeneracy pressure

  1. Jul 5, 2015 #1
    The QM degeneracy pressure puts up a fight but the immensity of the star wins out. Why is this? Is the Pauli Exclusion Principle really a principle? Why does it surrender in this case?
  2. jcsd
  3. Jul 5, 2015 #2


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    From white dwarf to neutron star, the electrons are forced to combine with protons to form neutrons. Neutron stars collapsing to black holes is unknown - could be quark gluon soup.
  4. Jul 5, 2015 #3
    Or if strings have anything to do with it, quark gluon soup with noodles.
  5. Jul 6, 2015 #4
    You can read the book of Pranab Gosh, "Rotation and Accretion Powered Pulsars", ch. 2 about this. But this phenomena is something like this: there is a range for every interaction all over the universe. For instance, almost all of the celestial objects are dipole dominated magnets but we don't see that they're pushing each other away (this is not exactly the same case but just an example). So, the Pauli exclusion principle is really a principle but in that kind of circumstances, I mean under such a huge degeneracy pressure and in such a tiny volume, it can not work as usual. All of the particles are lined up in the Fermi surface. In the so-called "well potential" examples as we know that the principle is valid, the mean range is always taken about the atomic range, 10^{-15} meters. For further info, you should read the chapter that I've mentioned above.
  6. Jul 7, 2015 #5

    Ken G

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    The Pauli exclusion principle never surrenders, all the principle says is that the electrons reach a ground state where they cannot lose any more heat. Losing heat is normally how a star gradually succumbs to gravity, but the PEP prevents that from proceeding to its ultimate conclusion. However, there is still a way that gravity can win out-- by releasing enough energy to make the electrons go relativistic before the whole system reaches its ground state. Relativistic electrons have a different relationship between momentum and kinetic energy, which makes them able to be in their ground state without uniquely specifying a radius-- any radius will do. This makes them susceptible to drastic contraction, especially if processes are going on (like neutronization) that remove kinetic energy via the escape of neutrinos. So we should not say the PEP surrenders, we should say that gravity finds a way to collapse the core without violating the PEP.
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