Can a locally non-special place emit Hawking radiation from a black hole?

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Discussion Overview

The discussion revolves around the nature of Hawking radiation and its origin, particularly questioning how a locally non-special place, such as the event horizon of a black hole, can be the source of this radiation. Participants explore alternative interpretations, including the possibility of particle tunneling from the singularity or quantum region into space outside the event horizon.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • One participant questions the conventional understanding of Hawking radiation as originating from the event horizon, suggesting it might be interpreted as particles tunneling from the singularity into outer space.
  • Another participant clarifies that Hawking radiation is a result of virtual particles appearing just outside the event horizon, with one particle escaping while the other falls into the black hole.
  • Some participants acknowledge that alternative interpretations could be valid if they align with calculations, expressing interest in whether tunneling has been studied in this context.
  • A model is referenced where pair production occurs behind the horizon, with a positive energy particle tunneling out, suggesting a connection to the traditional description of Hawking radiation.
  • One participant mentions a pedagogical paper that discusses the notion of "particle" in quantum field theory and its relation to Hawking radiation, indicating its usefulness for understanding the topic.
  • A later contribution presents a local description of particle creation by gravitational backgrounds, asserting that particle creation occurs only where the metric is time-dependent, specifically near the horizon in the case of Hawking radiation.

Areas of Agreement / Disagreement

Participants express differing interpretations of the origin of Hawking radiation, with no consensus reached on the validity of alternative models or the implications of tunneling from the singularity. The discussion remains unresolved regarding the interpretations of particle creation in this context.

Contextual Notes

Some participants note the limitations of their interpretations, such as the potential irrelevance of tunneling from the singularity due to the large macroscopic distance involved and the complexities of perturbative expansions around singularities.

wabbit
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Hello. I'm thinking about Hawking radation and there's one thing I find a bit strange. The radiation is usually described as originating at he even horizon. The explanation makes sense and all, but still how can this locally non-special place become the seat of a local phenomenon(emitting Hawking radiation) ?
So my question is : is it possible to interpret it diferently ? Could it possibly be described as particules tunelling from the singularity/quantum region into outer space (outside the event horizon) ? I guess this could be easy to rule out, maybe the decay of his tunelling with radius is all wrong... ? So does this make any kind of sense ?
 
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Hawking radiation is not emitted from the EH, it is a result of (simplistic description) virtual particles popping into existence just outside the EH and one of them crossing over and not being able to get back, so the other just wanders away.

Hawking himself has said that this whole "virtual particle" description of the radiation is an analogy, not a statement of fact. It is the only way he could think of to translate the math of what's actually happening into understandable English.
 
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Thanks, this makes sense. However, an alternative interpretation might be equally valid if it matches the calculation. I have no valid reason to think tunelling might be one, but I'd be interested to know if it's been studied...
 
wabbit said:
Thanks, this makes sense. However, an alternative interpretation might be equally valid if it matches the calculation. I have no valid reason to think tunelling might be one, but I'd be interested to know if it's been studied...

Yes, there is a model in which one component is the pair production which happens behind the horizon with the positive energy particle tunnelling out:
http://arxiv.org/abs/hep-th/9907001
 
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Maybe this pedagogic paper helps:

http://arxiv.org/abs/quant-ph/0609163

It discusses the notion of "particle" in QFT in chapter 9, and the relation with the Unruh effect and Hawking radiation in section 9.6. I found it very useful.
 
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Thanks everyone for taking the time to respond.

haushofer said:
Maybe this pedagogic paper helps:
http://arxiv.org/abs/quant-ph/0609163
It does! Also saved it for future reference.

sheaf said:
Yes, there is a model in which one component is the pair production which happens behind the horizon with the positive energy particle tunnelling out:
http://arxiv.org/abs/hep-th/9907001
Interesting. Tunnelling happens at the horizon so it looks related to the usual description.
I now think what I had in mind is most likely meaningless: I was talking about tunneling particles from the singularity to the horizon which, aside from the large macroscopic distance, seems to be like using "a perturbative expansion around a singularity".. Not so promising.
 
wabbit said:
Hello. I'm thinking about Hawking radation and there's one thing I find a bit strange. The radiation is usually described as originating at he even horizon. The explanation makes sense and all, but still how can this locally non-special place become the seat of a local phenomenon(emitting Hawking radiation) ?
An explicitly local description of particle creation by gravitational backgrounds (including those of black holes) is presented in
http://lanl.arxiv.org/abs/hep-th/0205022
It is shown that particle creation only happens at positions where metric is time dependent, and explained why in the case of Hawking radiation this means - near the horizon.
 

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