Questions tagged [hawking-radiation]

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 neighbor, allowing it to escape the gravitational potential.

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Irreversibility of Hawking radiation emission and Noether's theorem

Consider the following: In the process of emission of Hawking radiation, a pair of particles is created near the event horizon such that, while one particle falls through the event horizon and ...
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Does Hawking radiation propagate inward into the centers of rotating black holes?

Since most stars rotate and since the black holes so far observed appear to have resulted from the collapse of stars, I'm wondering whether the black hole radiation hypothesized by Hawking is expected ...
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Hawking radiation of fermions? [duplicate]

In most of literature, Hawking radiation is referred to a black-body radiation, with a temperature $ T =1/8\pi kM $ for Sch black holes. However, I reckon it is perfectly possible for black holes to ...
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Local acceleration of mirror in flat 1+1 spacetime

Setup: I am reading a paper (Carlitz and Willey. Phys.Rev.D. Vol35. pp.2327-2335. 1987) where the authors model Hawking radiation using a point-like accelerating "mirror" in 1+1 dimensional flat ...
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Why do larger black holes emit less Hawking Radiation than smaller black holes?

Pedestrian question from a non-physicist: I read on Wikipedia that larger black holes emit less net Hawking radiation than smaller black holes. This seems counterintuitive to me. If black holes are ...
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Thought experiment: ultra-fast outward push inside a black hole

Suppose I have a classical schwarzchild Black hole $B$ of mass $M$. And consider a spherical-subset (or sub-black-hole if you will) $B'$ (sharing the same singularity and having mass $M'$ (We will ...
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If photons have a finite mass, will black holes emit a factor 3/2 more electromagnetic Hawking radiation?

An old but wrong argument that photons must be exactly massless is to observe that black bodies radiate according to the Stefan–Boltzmann law and then argue that if photons were massive they would ...
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On the stability of black holes

Vera Rubin just passed (RIP) and recent News reviving the theory that the dark matter might be due to (small?) black holes; the idea that smaller black holes may be more prevalent than thought (then ...
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How entropy connect to “death” of a black hole?

I realized that everything in the universe can only increase in size and not decrease. Because the entropy is growing, but in the other hand, according to hawking a black hole which not "devour" ...
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Can you ride Hawking radiation away from a black hole?

Suppose you were held by a very strong rope at constant Schwarzchild coordinate $r = 2M (1 + \epsilon)$ just above the event horizon of a Schwarzchild black hole of mass $M$. You would feel a proper ...
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Do black holes radiate light? [duplicate]

I have a difficulty with understanding Hawking radiation. So far, I have "understood" (I can be wrong!), that the intense gravity of a black hole can split pairs of virtual particles so that one ...
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Shouldn't black holes “eat” their own radiation?

Black holes emit radiation (Hawking radiation) and sometimes even gamma radiation (when "eating" a star), but nothing can escape from a black hole. So the black hole should "eat" its own radiation. ...
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What does black hole formation and evaporation actually look like as viewed from far away?

Many people on Physics SE (myself included) have been confused about what black hole formation and evaporation look like when viewed from far away. For example: Does any particle ever reach any ...
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If virtual particles do not exist, how do they come to life at the event horizon?

Most of you (not me) know that virtual particles are only a nickname for some perturbation terms. So my question is how these perturbations become particles at the edge of an event horizon to create ...
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When two virtual particles are made real at the horizon of a black hole, does the curvature of spacetime decrease?

If two particles are created at the event horizon of a black hole (in popular language), the particle moving towards the hole will increase the mass of the hole. The event horizon though decreases in ...
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Is proton decay considered in neutron star models (and LHC)?

Although it is definitely not simple, there are many reasons to consider that baryon number can be violated, for example: during baryogenesis (just after Big Bang) there was created more matter than ...
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Does Hawking radiation require a black hole (event horizon)?

As a layman, I think I finally learned the origin of Hawking radiation (HR) thanks to excellent answers provided at An explanation of Hawking Radiation. Reading it, it bothered me that essentially if ...
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Thermalization in black holes in terms of infalling information

I was reading the "black holes as mirrors" paper by Hayden and Preskill which can be found here Anyways, I had a more generic question. If I throw a quantum state into a large black hole, what does ...
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How to find the Hawking temperature for this metric?

I am reading this paper about "Hawking radiation of Kerr-Newman-de Sitter black hole", where the authors find Hawking temperature of this metric The authors state that hawking temperature is given by ...
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Does Kerr metric have Hawking temperature?

Does Kerr metric with zero charge have Hawking temperature? What is it given by? I am reading a paper about and it says that the Einstein-Maxwell-Dilaton-Axion black hole and it says that temperature ...
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Does the Hawking Radiation give off X-rays?

Mostly I read that the x-rays are produced from the matter surrounding the black hole which spirals into the black hole due to its gravity and is consequently heated up. If the black hole has a main ...
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Wouldn't micro black holes in the atmosphere have noticeable effects?

If there are extra dimensions of space,the force of gravity would (in microscopic distances) increase way more than a factor of 4 times when the distance between masses is halved,which is the case in ...
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Can a stellar black hole revert into neutron star or whatever it was?

When a massive star cannot produce sufficient energy to counter it's weight the result is often a neutron star which is stabilized by quantum mechanical effects, say given enough mass to overcome such ...
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Won't Hawking radiation be sucked back into the black hole?

According to Stephen Hawking, black holes emit electromagnetic radiation(Hawking radiation), won't the EM radiations themselves be sucked back in by the black hole? I also read on wiki the following: ...
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Why do black holes have to disappear?

I read about Hawking radiation in Wikipedia and understood black holes may disappear over a long period of time. But my question is why does it have to disappear, because after some time of radiation ...
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Hawking radiation and relativity

Suppose that there is a black hole with such a mass (e.g. one thousand ton), so that it would evaporate (at rest, and no inflow of material or radiation) in ~80 seconds. If it is somehow accelerated ...
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Regarding black holes [closed]

If I could create a mini-black hole, yeah I know, it would evaporate away in a fraction of a nano-second, but would the energy emitted by the Hawking radiation kill me? Or would it produce only a tiny ...
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How Hawking Radiation can have any meaningful impact on the black hole's life since time is almost stopped right outside the Even Horizon?

Every object experiences time more and more slowly as they approach the event horizon until stops right at it, according to observers outside the event horizon. As far as I know quantum fluxuations ...
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Does Hawking radiation or something similar occur inside the event horizon?

The question Why is a black hole black? states that stuff can't escape the event horizon and must ceaselessly pull inwards towards the singularity. At the singularity the forces become infinite. ...
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Geodesic deviation in Hawking radiation

There is a point in the original derivation of Hawking's radiation that I don't see clearly. Following two null geodesics in the background of a collapsing star, one that will generate the future ...
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Would a black hole evaporate before reaching the event horizon? [duplicate]

Consider Alice approaching a black hole while Bob observes her journey from a distance. Due to the large gravitational field surrounding the black hole, Bob observes Alice her clock to slow down as ...
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How is it possible that pair production results in the decrease in a black holes energy? [duplicate]

I learned that pair production near black holes can cause them to loose energy, and eventually stop. But this is because quantum fluctuations cause particle and anti-particle pairs and the anti-...
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Do Black Holes emit Hawking radiation while engulfing normal mass?

As I read on various sites ,all of them say that Black Holes emit Hawking radiation as one of the instantly created virtual particles near Event Horizon escapes from it.One goes inside it and other ...
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Why does one particle in Hawking radiation have negative energy? [duplicate]

So as I understand it, Hawking radiation occurs when virtual antiparticle-particle pair are created near the event horizon of a black hole due to vacuum fluctuations because of Heisenberg uncertainty ...
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What's new about Hawking's theories in relation to 't Hooft's?

What's new about Hawking's theories in relation to 't Hooft's about resolving the black hole information paradox? Thanks "The information is stored in a super translation of the horizon that the ...
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What happen if Hawking radiation is not found?

I'm not a physicist but reading from a few popsci books. I read that Hawking has equations that explain Hawking Radiation precisely, right? Is this equation a proof that the radiation is real or we ...
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Does binary black holes evaporate slower because they compete for attracting virtual particles?

Is it true that if 2 black holes are near each other, such as binary black holes, will evaporate slower than when they are far apart, because they are competing for attracting virtual particles each ...
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Is Hawking radiation really the same as Unruh radiation

I read that Hawking radiation is the same as Unruh radiation. However, there seems to be a paradox here. If you have an extreme black hole (say with maximum charge), then it has temperature 0 and ...
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What happens to objects sucked into a black hole after the black hole evaporates away?

Suppose an object falls into a black hole that's so massive that it wouldn't get torn apart at the event horizon. What happens to it after the black hole evaporates away? According to the theory ...
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If Black holes are maximal entropy how can they evaporate?

According to Hawking/Bekenstein a black hole represents the highest amount of entropy for a given volume, (actually the entropy is related to the surface area of the black hole but the fact that they ...
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How would one attach black hole to starship in the Black hole Starship model? [closed]

A black hole starship is a theoretical idea for enabling interstellar travel by propelling a starship by creating an artificial black hole and using a parabolic reflector to reflect its Hawking ...
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Why does imaginary periodic time of the Rindler space of black hole give Hawking temperature?

The metric of a Schwarzschild black hole in Rindler coordinates is $$ds^2= -\frac{\rho^2}{(4MG)^2} dt^2 +d\rho^2 + d\mathbf x_\perp$$ where $\rho$ gives us the distance to the horizon. If we switch ...
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A doubt regarding Black Hole Complementarity

A friend was explaining Black Hole Complementarity to me, and at one point he said that to get a (horrendously) mixed quantum state, i.e. a thermal density matrix without a heat bath, one takes a ...
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Why would a black hole evaporate? [duplicate]

Hawking radiation doesn't make sense to me, with respect to black holes getting smaller. It would seem that any particle (or anti-particle) leaving the Schwartzchild radius would have a similar anti-...
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An explanation of Hawking Radiation

Could someone please provide an explanation for the origin of Hawking Radiation? (Ideally someone who I have been speaking with on the h-bar) Any advanced maths beyond basic calculus will most ...
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Is this analogy of Hawking Radiation correct?

Through reading of textbooks and other research papers, I have settled on the analogy of hawking radiation below (Written completely by myself) Within the ergosphere of the black hole, virtual ...
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If an object has a temperature, does it have to radiate?

I'm reading through a powerpoint presentation about Hawking Radiation (HR). They are explaining all of the reasons that built up to the postulate of HR, and one of the reasons is that if there is a ...
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Why does an evaporating black hole always stay a black hole?

Stars can only collaps and form black holes if their masses are above the Chandrasekhar limit, $M>M_{\rm Pl}^3/M_{\rm hydrogen}^2$. When the universe eventually cools down enough, the black holes ...
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Spaghettification on an atomic scale?

Spaghettification occurs when an object approaches a singularity. As one comes close enough to the singularity, the gravity at the feet (if this is a human) is greater than that at the head, ...
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How much energy is released by an evaporating black hole in the last second of its life?

From what I understand, due to Hawking radiation, black holes lose mass in the form of energy (electromagnetic radiation), with these characteristics: The larger the black hole, the less energy it ...

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