Violation of Pauli's Exclusion Principle possible?

In summary, according to this paper, violating PEP leads to changes in the state of matter, which may eventually lead to the collapse of a neutron star into a black hole.
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Aliasa
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I was reading some simplistic explanations of Pauli's Exclusion Principle (PEP) to explain a group of non-science people, and I came across this:

For Fermions, even as pressure builds, no two can be located in the same energy state. This causes them to "stack up" in effect. Only under great force can this(PEP) be overcome.

I have a problem with the last sentence. They go on to talk about Neutron Degeneracy Pressure and formation of black holes, but I'm unsure whether PEP is actually being violated there. Can anyone shed a light?
 
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No the PEP cannot be violated. I think what they want to say is that at too high masses neutron stars become unstable against gravitational collapse. For compact objects you always have a counterbalance between pressure and gravitation. The PEP causes a big pressure, i.e., you cannot squeeze indistinguishable fermions easily together. That's why you can have quite heavy neutron stars (not too long ago one has observed neutron stars with two solar masses!). But at one point this degeneration pressure cannot withstand the gravitation, and the object collapses to a black hole.
 
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Aliasa said:
I was reading some simplistic explanations of Pauli's Exclusion Principle (PEP) to explain a group of non-science people, and I came across this:

For Fermions, even as pressure builds, no two can be located in the same energy state. This causes them to "stack up" in effect. Only under great force can this(PEP) be overcome.

I have a problem with the last sentence. They go on to talk about Neutron Degeneracy Pressure and formation of black holes, but I'm unsure whether PEP is actually being violated there. Can anyone shed a light?

From looking at this paper-
Neutron Star Interiors and the Equation of State of Superdense Matter
http://arxiv.org/abs/0705.2708v2

The impression I got is that the increase in equation of state [itex](w=P/\rho c^2)[/itex] brings on a change in the state of matter (note, for regular matter, w=0). For instance, looking at a typical neutron star, the equation of state (eos) at the centre is predicted to be w=0.59; for a hyperon star (neutron star with hyperons at the core), w=0.42 to 0.31 at the centre; and for a hybrid neutron star (with quark matter at the centre), w=0.21. The interesting thing here is that in the transition from neutron matter to quark matter, the density increases but the pressure seems to actually drop*. This gives the impression that as matter approaches w=1, there's a change in the state of matter, it may be that quarks break down into something else (there is the hypothetical preon) and this process keeps going until reaching Planck density/pressure where w=1 (or at least close to it). It's possible that virtual particles will play some part in halting the collapse before Planck density/pressure is reached.

*According to the paper, the quantities for the hyperon star at the centre are density- 2x109 tonnes/cm3 and the pressure is between 6 to 8x1034 N/m2 while for the hybrid star the density at the centre is 3x109 tonnes/cm3 and the pressure is 5x1034 N/m2.
 
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Aliasa said:
Only under great force can this(PEP) be overcome.

I have a problem with the last sentence.
I have a problem with that too. From one side it is claimed that PEP can't be violated but from other side it is said that black holes do form despite PEP.

So I have tried to understand what happens according to QM if you try to violate PEP.
One direct conclusion is that distribution of particles across different energy levels changes from Maxwell–Boltzmann statistics to Fermi–Dirac statistics.
Another more speculative conclusion is that particle collisions that involve degenerate matter can't be modeled classically (because "classical collisions" imply Maxwell–Boltzmann statistics).
 

What is Pauli's Exclusion Principle?

Pauli's Exclusion Principle is a fundamental principle in quantum mechanics that states that no two identical fermions (particles with half-integer spin) can occupy the same quantum state simultaneously.

How can Pauli's Exclusion Principle be violated?

Pauli's Exclusion Principle can be violated under extreme conditions such as high temperatures or pressures, or in very dense environments where the particles are forced to occupy the same quantum state.

What are the consequences of violating Pauli's Exclusion Principle?

Violation of Pauli's Exclusion Principle can lead to the collapse of the system, as it goes against the fundamental laws of quantum mechanics. It can also result in the emission of high-energy particles.

Is there any evidence of Pauli's Exclusion Principle being violated?

There have been some reports of possible violations of Pauli's Exclusion Principle in experiments involving heavy ions and nuclear reactions, but these claims are still controversial and require further investigation.

How does the violation of Pauli's Exclusion Principle impact our understanding of the universe?

The violation of Pauli's Exclusion Principle challenges our current understanding of quantum mechanics and the behavior of matter at a fundamental level. It also has implications for our understanding of the evolution of the universe and the formation of stars and planets.

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