Radiation that comes from pair production quantum effects in close vicinity to an event horizon, leading to the potential for eventual evaporation of black holes. Two mirror particles are created with one falling behind the horizon, becoming casually lost to the rest of the universe, including its ...

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Black holes and positive/negative-energy particles

I was reading Brian Greene's "Hidden Reality" and came to the part about Hawking Radiation. Quantum jitters that occur near the event horizon of a black hole, which create both positive-energy ...
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Why does Stephen Hawking say black holes don't exist?

Recently, I read in the journal Nature that Stephen Hawking wrote a paper claiming that black holes do not exist. How is this possible? Please explain it to me because I didn't understand what he ...
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From where (in space-time) does Hawking radiation originate?

According to my understanding of black hole thermodynamics, if I observe a black hole from a safe distance I should observe black body radiation emanating from it, with a temperature determined by its ...
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517 views

Extremal black hole with no angular momentum and no electric charge

A black hole will have a temperature that is a function of the mass, the angular momentum and the electric charge. For a fixed mass, Angular momentum and electric charge are bounded by the extremality ...
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547 views

Hawking radiation and reversibility

It's often said that, as long as the information that fell into a black hole comes out eventually in the Hawking radiation (by whatever means), pure states remain pure rather than evolving into mixed ...
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6answers
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Do all massive bodies emit Hawking radiation?

It is known that any accelerated observer is subject to a heat bath due to Unruh radiation. The principle of equivalence suggests that any stationary observer on the surface of a massive body should ...
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563 views

Do apparent event horizons have Hawking radiation?

As I understand it, black holes have an absolute event horizon and an apparent horizon specific an observer. In addition to black holes, an apparent horizon can come from any sustained acceleration. ...
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189 views

Hawking Radiation as Tunneling

Firstly, I'm aware that Hawking radiation can be derived in the "normal" way using the Bogoliubov transformation. However, I was intrigued by the heuristic explanation in terms of tunneling. The ...
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Information scrambling and Hawking non-thermal radiation states

Could a very small black hole where half of its entropy has been radiated, emit Hawking radiation that is macroscopically distinct from being thermal? i.e: not a black body radiator. Or would the ...
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434 views

How do we know that black holes evaporate?

This has been bugging me for some time. As I understand it, Hawking radiation is the result of the mismatch between the vacuum state of a quantum field as seen by a free falling observer (falling ...
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2answers
412 views

Are there any other mechanisms that can make virtual particles 'real' other than Hawking Radiation and Universe Births?

As I understand it, if virtual particles do not recombine within the plank time they become 'real'. This is proposed to happen in Hawking Radiation, where one virtual particle crosses the black ...
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Analog Hawking radiation

I am confused by most discussions of analog Hawking radiation in fluids (see, for example, the recent experimental result of Weinfurtner et al. Phys. Rev. Lett. 106, 021302 (2011), ...
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3answers
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Why is there a flux of radiation in the Hawking effect but not in the Unruh effect? (and other questions)

This question is slightly related to this one Do all massive bodies emit Hawking radiation?, which I think was poorly posed and so didn't get very useful answers. There are several questions in this ...
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If I fall into an evaporating black hole, where do I end up?

This question has been bothering me for a while. I have a crude hypothesis... As I understand it, an observer falling into a black hole will cross the event horizon at some specific future (proper) ...
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1answer
306 views

In there such a thing as the Black Hole Information Paradox?

When I first heard about the black hole information paradox, I thought it had no content. At the time, papers about it had been written for numerous years and they keep on coming. Now that the press ...
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4answers
474 views

Hawking Radiation - Why it causes black holes to die?

If a particle is being expelled from the Black Hole and an antiparticle is being driven into it, shouldn't the opposite occur as well and in the same frequencies? I mean Black holes should emit ...
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1answer
142 views

Multipolar expansion profile of Hawking radiation on Kerr black holes

I would be very curious if Kerr black holes emit Hawking radiation at the same temperature in the equatorial bulges and in their polar regions. I've been looking some reference for this for a couple ...
6
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1answer
693 views

On black holes, Hawking radiation and gravitational atoms

Over the past hour or so I've been following one of my standard physics-based, wanders-through-the-internet. Specifically, I began by reviewing some details of dark energy theory but soon found myself ...
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8answers
663 views

Flat space limit of the Schwarzschild metric and Hawking temperature

The Schwarzschild metric reduces to the Minkowski metric in the limit of vanishing $M$, but the Hawking temperature which is proportional to $1/M$ diverges in the same limit. This would imply that ...
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55 views

Gravastars: Are they observationally distinguishable from Black-Holes?

Are observations of Hawking radiation at the acoustic event horizon in Bose-Einstein condensates consistent with Gravastars? To reconcile the second law of thermodynamics with the existence of a ...
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Is the Hawking radiation of a charged black hole thermal?

Suppose you have a Schwarzschild black hole of mass $M$ and angular parameter $a = 0$ (no rotation). Question: is it possible to throw a charge $Q$ at a faster rate than it will be re-radiated? Will ...
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4answers
538 views

de sitter cosmologic limit

It has been said that our universe is going to eventually become a de sitter universe. Expansion will accelerate until their relative speed become higher than the speed of light. So i want to ...
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2answers
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Intensity of Hawking radiation for different observers relative to a black hole

Consider three observers in different states of motion relative to a black hole: Observer A is far away from the black hole and stationary relative to it; Observer B is suspended some distance ...
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2answers
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Hawking radiation from point of view of a falling observer

This paper tells that Hawking claimed that the falling to a black hole observer will not detect any radiation. But only because the frequency of the Hawking radiation will be of the order $1/R_s$ so ...
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0answers
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Black hole entropy from collapsed entangled pure light

Consider the following scenario, very similar to the one proposed in this question, but this time, the pure quantum radiation used for the black hole collapse, is now being split with down-converter ...
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2answers
185 views

Will the black hole evaporate in finite time from external observer's perspective?

There is the problem that is bothering me with the black hole evaporation because of Hawking radiation. According to Hawking theory the black hole will evaporate in finite time because of quantum ...
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2answers
268 views

How can one reconcile the temperature of a black hole with asymptotic flatness?

A stationary observer very close to the horizon of a black hole is immersed in a thermal bath of temperature that diverges as the horizon is approached. $$T^{-1} = 4\pi \sqrt{2M(r-2M)}$$ The ...
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1answer
290 views

Hawking Radiation: how does a particle ever cross the event horizon?

The heuristic argument for Hawking Radiation is, that a virtual pair-production happens just at the event horizon. One particle goes into the black hole, while the other can be observed as radiation. ...
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3answers
408 views

Why can't light escape from inside event horizon of Black Holes?

The simple answer: Its because Gravity of Black Hole there doesn't allow it. See also this and this Phys.SE posts. Isn't it a classical answer? When we're unable to connect Gravity with Quantum ...
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Are information conservation and energy conservation related?

as evident from the title, are both, conservation of energy and conservation of information two sides of the same coin?? Is there something more to the hypothesis of hawking's radiation other than ...