Can quantum entangled particles be split and sent into a black hole

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Discussion Overview

The discussion revolves around the concept of quantum entangled particles in relation to black holes, specifically whether one half of a quantum entangled pair can be sent into a black hole and the implications of virtual particles at the event horizon. The scope includes theoretical considerations, models of particle behavior near black holes, and interpretations of existing literature.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested
  • Mathematical reasoning

Main Points Raised

  • One participant questions whether virtual particles and their behavior at the event horizon relate to quantum entangled particles, suggesting a possible connection.
  • Another participant asserts that the idea of virtual particles being split at the event horizon is a myth, challenging the premise of the initial question.
  • References to Stephen Hawking's work are made, noting that he himself commented on the lack of a mathematical description for the process of virtual particles at the horizon.
  • Discussion includes the 1999 paper by Parikh and Wilczek, which proposes a model involving quantum tunneling from behind the horizon, but participants express uncertainty about the assumptions made in this model.
  • Concerns are raised about the assumptions in the Parikh and Wilczek model, particularly regarding the spontaneous formation of electromagnetic waves and the implications for classical general relativity.
  • Some participants discuss the mathematical treatment of tunneling probabilities and the implications for the information paradox related to black holes.
  • There is a debate about the nature of particles behind the horizon, with differing interpretations of whether they are virtual or can arise from non-gravitational mechanisms.
  • One participant suggests a comparison of the black hole radiation process to ordinary quantum physics, questioning the assumptions made by Parikh and Wilczek.

Areas of Agreement / Disagreement

Participants express differing views on the nature of virtual particles and their relationship to quantum entanglement, with no consensus reached on the validity of the initial premise or the interpretations of the Parikh and Wilczek model.

Contextual Notes

Participants highlight limitations in the assumptions made in the discussed models, particularly regarding the spontaneous formation of waves and the applicability of classical general relativity in the context of black hole physics. The discussion remains open-ended with unresolved mathematical steps and interpretations.

Benfield
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TL;DR
Virtual particles
I am new here so apologies in advance. When a virtual particle and anti particle appear at the event horizon of a black hole, before they destroy each other, they are split with one being sucked into the black hole and the other becoming exhaust. Are these the same particles as the quantum entangled ones, with one corresponding to the other, or if not is it possible to send one half of a quantum entangled particle into a black hole?
Thanks sorry to those who are shaking heads.
 
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Benfield said:
When a virtual particle and anti particle appear at the event horizon of a black hole, before they destroy each other,

That doesn't happen. It's a pop-science myth. That renders the rest of your question moot.
 
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The myth of a virtual particle pair, one falling to the horizon, was started by Stephen Hawking himself in his 1975 paper. Later he commented that "no one has been able to give a mathematical description of that hypothetical process."

https://arxiv.org/abs/hep-th/9907001

The famous 1999 paper by Parikh and Wilczek describes a model where a quantum tunnels from behind the horizon. The paper contains some assumptions which are not obvious to me.
 
Heikki Tuuri said:
The famous 1999 paper by Parikh and Wilczek describes a model where a quantum tunnels from behind the horizon. The paper contains some assumptions which are not obvious to me.
What assumptions?
 
Demystifier said:
What assumptions?

Parikh and Wilczek assume that a spherical electromagnetic wave, which travels radially outward, can spontaneously form just behind the horizon and the horizon can contract because the mass-energy omega of that wave is not to be counted in the mass M of the black hole when the wave travels outward.

We do not know if any of the above assumptions are true in nature.

Classically, such a wave cannot form spontaneously. Why can we use classical general relativity to argue about the radius of the horizon then?

What controls the rate at which various quanta are produced?
 
Heikki Tuuri said:
Parikh and Wilczek assume that a spherical electromagnetic wave, which travels radially outward, can spontaneously form just behind the horizon
They don't assume that it forms spontaneously. They assume that it appears there through the process of quantum tunneling. The probability of tunneling is computed via the standard WKB formula.

But I have a different reservation about their approach. The principal value of the integral in (6) is real, so the imaginary part is zero, implying that the probability of tunneling is zero. But they choose not to take the principal value, but a value obtained with a deformed contour of integration which results in the non-zero result (7). It looks quite ad hoc to me.

Another deficiency of their approach is that they do not compute the quantum state after (or even before) the tunneling. In this way they cannot say much about the information paradox.
 
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Demystifier said:
They don't assume that it forms spontaneously. They assume that it appears there through the process of quantum tunneling. The probability of tunneling is computed via the standard WKB formula.

Maybe I did not understand something in the paper.

Parikh and Wilczek write above equation (5):
The imaginary part of the action for an s-wave outgoing positive energy particle which crosses the horizon outwards from into out can be expressed as

The imaginary part of the action, I am S, tells the probability that the particle tunnels through the potential wall. That is the WKB approximation.

I understood the paper like this: a virtual photon representing the outgoing spherical wave appears spontaneously behind the horizon.

After tunneling through the horizon the photon has stolen some energy from the black hole, and it leaves as a real particle.

Let us compare this to how a real photon is born in ordinary quantum physics. There is an electric charge in an accelerating motion. Classically, there would be electromagnetic radiation. If quantum mechanics allows the system of charges to fall into a lower energy state, then a quantum of energy, a photon, may leave.

The emission of a photon from a black hole does not have a classical counterpart. That is one of the reasons why I do not see the assumptions of Parikh and Wilczek as obvious.

EDIT:
Can we draw a Feynman diagram style description of the process? We may assume that in a collision experiment, a large number of particles create a bound state, a black hole. Then a virtual photon steals energy from this bound state and becomes real. Unfortunately, Feynman diagrams do not allow bound states.
 
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Heikki Tuuri said:
I understood the paper like this: a virtual photon representing the outgoing spherical wave appears spontaneously behind the horizon.
They never said that the photon behind the horizon was virtual. They did not say how exactly it appeared there, but it could have been created by some "ordinary" non-gravitational mechanisms.
 
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I have spent quite some time analyzing the Parikh and Wilczek paper. I will do more analysis some time in the future. A theory of quantum gravity should clarify which assumptions in the paper are correct.

A few other points: the radiation in the Hawking 1975 paper is not visible to a freely falling observer. The Parikh and Wilczek radiation is probably visible.

In an idealized case, the black hole is spherically symmetric. Can it create transverse radiation? The symmetry would be broken.
 
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