[jeffreyH (OP)]

Can 2 particles collapse into a black hole? What if the particle is elementary rather than composite? What part would the Pauli exclusion principle play in this interaction?

[petelamana]

Great question.  Let me take a layman's stab at this...

I assume you're asking could two 1-Planck scale particles, and 2-Planck scale particles?  However, isn't a Planck scale particle, by definition a theoretical particle thought to be a tiny black hole whose Compton wavelength is equal to its Schwarzschild radius?

[Bill S]

What part would the Pauli exclusion principle play in this interaction?

If the particles are fermions, the Pauli exclusion principle prevents them from occupying the same quantum state simultaneously. 

My first question would be: In order to form a BH, would the particles have to occupy the same quantum state?

[jeffreyH (OP)]

That's not even considering charge.

[evan_au]

If the particles are fermions (½ integer spin), wouldn't they automatically have 2 quantum states available: spin up and spin down?

[jeffreyH (OP)]

If the particles are fermions (½ integer spin), wouldn't they automatically have 2 quantum states available: spin up and spin down?

Yes. I am interested in the things that may prevent the collapse of the 2 particle system. If there are any at all that is.

[jeffreyH (OP)]

Great question.  Let me take a layman's stab at this...

I assume you're asking could two 1-Planck scale particles, and 2-Planck scale particles?  However, isn't a Planck scale particle, by definition a theoretical particle thought to be a tiny black hole whose Compton wavelength is equal to its Schwarzschild radius?

Theoretically, a Planck mass particle on its own would not collapse. It has a critical mass beyond which collapse is inevitable. If theory is correct. Two Planck mass particles together should form a black hole.

[petelamana]

Quote from: evan_au on Yesterday at 03:36:30 pm
If the particles are fermions (½ integer spin), wouldn't they automatically have 2 quantum states available: spin up and spin down?

Yes. I am interested in the things that may prevent the collapse of the 2 particle system. If there are any at all that is.

Don't we have to consider H-stability?  For example, if its spatial integral is negative, the system is proven to be catastrophic and collapse will occur.