All Questions
26
questions
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57
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Scattering approach for massless scalar Hawking radiation and Bogoliubov coefficients in Schwarzschild metric
Reflection coefficient from the scattering approach in tortoise coordinates, looks exactly like relationship between modulus squared of Bogoliubov coefficients. However I'm not able to figure out a ...
0
votes
1
answer
121
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Black hole information paradox
I read that it is generally believed that information is preserved in black hole evaporation, and people's views only diverge when it comes to how information is preserved. Is this true?
- 117
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0
answers
41
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Why are greybody factors necessary when dealing with Hawking radiation?
According to Wikipedia, greybody factors are corrections to the black hole Hawking radiation spectrum. They say that at the horizon the emission is that of a perfect black body, but the gravitational ...
- 22.1k
1
vote
0
answers
89
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Is Hawking radiation possible for all massive objects (based on new research)? [duplicate]
So a few years ago, looking at the answer to this question the answer was no and that there needed to be an event horizon for hawking radiation to arise and that it is not purely curvature that causes ...
- 1,534
2
votes
0
answers
63
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Interior Hawking radiation
The Hawking effect is induced by the causal horizon of a black hole, which separates the interior and exterior modes such that asymptotic observers at infinity see thermal radiation flux. What can we ...
- 1,221
1
vote
1
answer
194
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How to derive form of reflecting waves from black holes?
Consider a collapsing sphere that becomes a black hole. The interior schwartzchild lightcone coordinate $U$ can be written as $U$ = $\tau - r + R_{0}$ where $R_{0}$ is the radius of the sphere before ...
user310742
0
votes
1
answer
96
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Does Hawking radiation have a statistical physics origin like the usual derivation of Boltzmann factors?
According to Andrew Steane's Thermodynamics chapter 19 on Thermal radiation:
"The total emission from a physical object can usefully be separated in two parts: the thermal radiation and the rest. ...
- 2,100
1
vote
1
answer
45
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What happens to the entropy of the pre-existing information on a black hole event horizon as more mass falls into the hole?
Does the old entropy stay the same as new bits of information are added to increase the overall entropy?
user355436
2
votes
2
answers
104
views
Does black hole entropy change as a gravitational wave passes it?
The black hole entropy depends on the area of the event horizon.
Do gravitational waves change this area?
Does the entropy increase and then decrease as the horizon stretches and contracts?
user355436
2
votes
1
answer
101
views
Is there an information paradox even without gravity?
The standard setting for the black hole information paradox is semiclassical gravity, where quantum fields backreact on the metric via the expectation value of their stress-energy tensor. Then the ...
- 1,455
1
vote
2
answers
153
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Is the experimental evidence confirming black hole entropy or Unruh radiation?
The question says it all: how does Bekenstein–Hawking entropy or radiation fare when compared with observation?
Or maybe just the idea of Unruh radiation?
user85598
9
votes
3
answers
332
views
Quantum pressure and chemical potential for a Schwarzschild black hole?
Just as Hawking showed that even Schwarzschild black holes have a temperature, shouldn't they also have a pressure and chemical potential? Are there any analytical formulae of those as well as
$$ T_{...
- 6,611
1
vote
2
answers
116
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Is formation of a black hole thermodynamically favourable?
Isn't it like that the black hole is just swallowing suns and other parts of cosmos, and thus continuously absorbing matter. I know that it emits radiations also, which should be negligible in terms ...
- 239
3
votes
1
answer
343
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Why is black hole information paradox a problem when there are no real black holes in the Universe?
We know stars take infinite time in our coordinates to actually collapse into a black hole due to time dilation. See, e.g., How can anything ever fall into a black hole as seen from an outside ...
- 39
19
votes
6
answers
5k
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Why doesn't Hawking radiation add to the mass of a black hole just as much as it subtracts from it? [duplicate]
If 'quantum foam'-generated particles are made of matter and antimatter in equal amounts, why don't the matter particles that fall into the black hole add to the black hole's mass just as much as the ...
- 4,509