Recent content by Demystifier

This looks like a black hole firewall scenario, on which you may google for more info.

No, it only says that a person will always survive a quantum version of "Russian roulette".

No, your consciousness is split into all universes in which you are alive.

Is analogue Hawking radiation, namely radiation of phonons in systems with sonic horizon, "known" physics?

Then something less mundane https://arxiv.org/abs/1311.4363

How about putting spherical mirror around the black hole?

The norm that you consider, as a function of ##a##, has a jump at ##a=0##. Therefore you cannot find the value at ##a=0## by considering the limit ##a\to 0##.

Yes.

Yes, but in that case you are no longer considering two photons. And by the way, the expression "Feynman rules" means something entirely different, it's related to perturbative Feynman diagrams, not to Feynman path integrals.

When you have two entangled photons, there is no such thing as amplitude of photon 1. There is only an amplitude for both photons together.

Electrodynamics (interaction of EM field with charged fields) is also nonlinear, but quantum electrodynamics is linear and the superposition principle is valid. The point is that electrodynamics, gravity, etc. are non-linear in the sense that Hamiltonian is a non-quadratic function of fields...

For a visualization, consider the surface of a cylinder. It is curled in one direction, but flat in another.

That's wrong. Have you ever seen any equation in quantum mechanics for a system with two or more particles?

No, both photons together are "one particle" in 6 dimensions.

I guess we are talking about nonrelativistic QM, not about QFT. If you have two particles, each moving in 3 dimensions, you can think of it as one particle in 6 dimensions. Write the path integral by pretending it's one particle in 6 dimensions, and you will get the right result.