system
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human
What causes the force that results from the Pauli exclusion principle?

I was reading about white dwarf stars in Stephen Hawking's "Brief History of Time", and he states that the only thing preventing a white dwarf from collapsing into a black hole is the repulsive force provided by the Pauli exclusion principle, but for stars with masses past the Chandrasekhar limit, this force is eventually overcome by gravity. My question is where does this force come from (does it have a force carrier) and can it be explained in terms of the four elementary forces? Also as an aside, how can the exclusion principle be "overcome" by gravity? Does the law simply break down with forces that large?
gpt
>(does it have a force carrier) and can it be explained in terms of the four elementary forces?

No. Pauli exclusion doesn't fall under any of the fundamental forces. It would still exist for identical fermions that don't self-interact at all. It's just a lack of available states where any two identical fermions share all the same quantum numbers.

>Also as an aside, how can the exclusion principle be "overcome" by gravity? Does the law simply break down with forces that large?

Pauli exclusion affects the equation of state of the matter in the white dwarf. When you have degenerate matter, it strongly resists being compressed anymore, and ultimately this is due to Pauli exclusion. So the inward force that you need to apply to compress it further becomes too high for the stars own gravity to do so. It's a hydrostatic equilibrium between an outward pressure gradient and an inward gravitational force.