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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Can a black hole be considered as a gray body?

The emissivity of a gray body is constant but is considered to be less than 1. Since the black hole is considered near perfect black body but not a perfect black body its emissivity will be less than ...
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We can't use numerical simulation for Hawking radiation backreaction, right?

In the last passage of 1975 paper Hawking tells that we can't use a local stress-energy tensor to tackle the backreaction of radiation since creation of particles is a non-local and global process ...
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Why isn't Hawking Radiation Neutral? [duplicate]

My understanding of Hawking Radiation is that it is a pair of virtual particles that pop into existence at the edge of an even horizon. The anti-particle falls into the event horizon thus slightly ...
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The Information Paradox and the Copenhagen Interpretation

I'm curious why the so-called 'information paradox' is a paradox. I know that it's regarded as a paradox due to the fact that Hawking radiation seemingly violates the unitarity of the time-evolution ...
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Is Hawking radiation real for a far away observer?

It is my understanding that Hawking radiation is observed by external observers, and A necessary condition for having Hawking radiation is the formation of an event horizon during a gravitational ...
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How does the Unruh effect create particles?

I've read that the Rindler horizon cuts off access to fundamental quantum fields and leads to a mixing of positive and negative frequencies via the Bogoliubov transformations. But here is where I have ...
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Can Hawking radiation be observed from the radiation (spectrum) of M87*?

Using $M87^*$ data from EHT observation (mass, temp of the surrounding accreting disk) and approximating area of EH by euclidean geometry $4\pi r^2)$, error comes around of order one or two. One gets ...
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Hawking Radiation and Information loss

The Gravity program I watched brought something really interesting to my awareness. With black-hole Hawking radiation... everything gets sucked into the event horizon... we don't know what happens ...
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What information can there be in black body radiation?

It seems to be part of the theory of Hawking radiation that the spectrum is black body and that it therefore cannot carry any information...thus creating a conflict with the conservation of ...
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Why don't baby black holes give off a lot of Hawking radiation and vanish before having the chance to grow?

Is it because they eat more than they eject? Or something else? Edit ------- I mean black holes which have just started forming from stellar collapse. Should had mentioned this. Edit 2 ----- When you ...
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Can a particle just below the event horizon of a tiny, fast shrinking black hole make a comeback?

A particle has just entered a minuscule (and non-rotating) black hole which is at the end of its life. The black hole is getting smaller really fast as it boils away ejecting tonnes of Hawking ...
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Thermodynamics of Hawking radiation and cosmic microwave background

Black holes can emit Hawking radiation. The larger the mass of a black hole the lower the frequency of emitted radiation (aka the temperature of the object). Hawking radiation of a large enough black ...
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Direction of Unruh radiation

In case of a black hole, the direction of the Hawking radiation is from the horizon to the observer. The corresponding effect in the Rindler spacetime is the Unruh radiation. Intuitively, a rapidly ...
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Hawking radiation and virtual Exotic matter [duplicate]

Are the negative energy modes absorbed by the blackhole virtual exotic matter and when a blackhole hawking radiates does it produce matter and antimatter in equal amount and how do virtual particles ...
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Uncertainty in mode number operator and Hawking's original paper

I began reading Hawking's paper Particle Creation by Black Holes (1975, Commun. math. Phys 43, 199—220) but am a little confused by what he writes at the bottom of the second page. The idea is that ...
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Kerr black hole evaporation time question

Is there any closed (even if complicated) formula por the Hawking evaporation time for a Kerr black hole (and more general black holes) just like the one \begin{equation} t_e=\dfrac{5120\pi G^2M_0^3}{\...
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Is this a correct description of Hawking Radiation? [duplicate]

The zero point energy of a vacuum is different depending on speed and gravity. The zero point energy of the curved geometry of spacetime near a blackhole is higher compared to a distant observer, so ...
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Hawking radiation of mass

As a layperson reading Yes, Stephen Hawking Lied To Us All About How Black Holes Decay, if I understand correctly Hawking radiation is a property of the curvature of space and not specifically of ...
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Question about hawking radiation propagation through space

So, according to Bogolyubov transformation and the equivalence principle, one can describe the Hawking/Unruh temperature at a distance $r$ from the center of a black-hole (except inside the horizon) : ...
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What is the current status on black hole information paradox?

I assume information must be somehow preserved either by time dilation so object can take its time to reach the horizon and hawking radiation slowly kicks the information out as real particle as well ...
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Does Hawking radiation can have any observable effect on Black hole shadow

Last year we captured shadow of black hole at the centre of M87 by Event Horizon telescope. I am wondering if Hawking radiation can have any effect on the black hole shadow. The more I think about ...
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Is the calculation done in Hawking's original paper is done using perturbation?

In the paper Particle creation by black holes when calculating $p_{\omega}$, Hawking does the calculation in following manner let $p_{\omega}^{(1)}$ denotes the radiation which gets scattered by ...
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Before Hawking temperature, why did absence of radiation mean black holes had no temperature?

Before Hawking radiations were discovered, people said black holes had no temperature even though we could extract energy from them using the Penrose process (which also leads to a relation similar to ...
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Dilaton background in Replica wormholes publication

Refering to the paper "Replica Wormholes and the Entropy of Hawking Radiation" by Almheiri et al. in arXiv:1991.12333. The authors consider Jackiw-Teitelboim gravity theory describing a ...
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Could there be a magnetic version of Hawking radiation?

From my, probably flawed, understanding of Hawking Radiation, virtual particles get turned into non-virtual particles. I'd imagine since both Gravity and Electromagnetism both follow the inverse ...
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What is a lukewarm black hole?

What is a lukewarm black hole? They supposedly have something to do with hawking radiation. I would like an explanation of their properties.
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Disintegrating as you enter a large black hole, instead of experiencing what's inside?

I'm having trouble reconciling these three things I've heard about black holes: If you fall into a sufficiently large black hole, you won't experience anything in particular when crossing the event ...
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Planck's constant, Boltzmann constant and Hawking Temperature

Hawking temperature of a Schwarzschild black hole is defined in SI units as: $$T_{H}=\frac{\hbar c^3}{8 \pi G k_{B} M}$$ where $k_{B}$ is the Boltzmann constant. I would like to know how $\hbar$ and $...
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Can white holes undergo hawking radiations like black hole?

Could white holes undergo reverse hawking radiation? This is because of quantum mechanical uncertainty. So for example a pair of particles one a positive and one a negative energy particle. The ...
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Unification of forces in black hole singularity?

If at the center of a black hole a singularity or singularity-like state is reached, wouldn't you have the fundamental forces reaching unification energy? In which case, it would seem that a black ...
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The nature of event horizons

I am a layman, so I'm not completely up on the latest black hole theories. However, I have been thinking about how an event horizon can be be penetrated by matter outside of the event horizon. Now, ...
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Hawking radiation and the removal of singularities

Using QFT in curved spacetime, Hawking was able to show that black holes evaporate. Whilst this has never been observered, the commonly excepted statement is that black holes continually radiate until ...
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Particles reaching a singularity [closed]

If the gravity well steepens to infinity at the point of a singularity, then so does the "time well". Understandingly, the inward falling energy/matter is not aware of this change in time relative to ...
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Fall of temperature of a radiating body

While going through the idea for the hawking radiation,the argument was "As T is inversely proportional to the product of GM(planck), so as black hole radiates energy ,then temperature will ...
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Alternative to Dark Energy

If Black Holes consume mass and re radiate it in the form of massless photons the mass of the universe is declining. Could this explain the accelerating expansion of the universe without the ...
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A good introductory reference for Hawking radiation?

I am looking for a good reference to study the Hawking effect in detail. Hawking's original paper is a nightmare. I first tried this introductory paper but it skips a lot of details, Ford's QFT notes ...
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Sign of gravitational action

I am reading this paper on Black hole phase transition in AdS, but for the life of me I cannot get the signs right for the expression of the Action of a Black Hole in AdS (eq (2.9)). Consider the AdS ...
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Ways to calculate Hawking radiation of black hole

As the title suggest what are different ways by which one can calculate Hawking radiation of a black hole? I only know the standard bogoliubov transformation method.
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Hawking radiation and evaporation of black holes [duplicate]

Why black holes lose mass and energy by evaporation?
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A question on the death of a black hole

I was recently watching a video about the life of the universe at its end... and then tried to correlate that to what I could find in recognized papers that I could download. (as I am not a scientist ...
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Hawking radiation in the complexity picture

If we take the perspective that black holes thermalize (reach maximum entropy) in a very short time and then just sit there and grow in complexity, how do we interpret Hawking radiation in this ...
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Does Hawking Radiation lead to Black Hole Evaporation / Reduction of Black Hole Mass?

As I understand, Hawking radiation leads to black hole evaporation, resp. a black hole would lose mass due to that effect. Now Hawking radiation is very similar to Unruh radiation, i.e. some (...
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Can a Black Hole become a normal mass again?

It is well known how Black hole forms. But once it is formed are there any circumstances which can lead a black hole to becoming a normal mass again?
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Can the Higgs particle escape a black hole? [duplicate]

The higgs particle or field is what gives mass to everything. It's said that nothing can escape a black hole. If that is true how can the black hole "tell" its mass as even the higgs would not be able ...
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What is the experimental evidence - direct or indirect - for Hawking or Unruh radiation?

I'm wondering what evidence exists, direct or indirect, for Hawking or Unruh radiation. I believe one of the initial goals for the Fermi LAT mission was to look for evaporating microscopic black ...
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Is there gravitational black hole radiation? [duplicate]

Black holes have entropy and temperature. As Bekenstein and Hawking showed, this yields the emission of electromagnetic radiation in the form of photons: black holes radiate photons. The next ...
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Thermalization in non-disordered systems

The eigenstate thermalization hypothesis explains the mechanism of the thermalization of generic many-body quantum systems. The presence of disorder, on the other hand, provides an elegant example of ...
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Hawking Radiation Inverted [closed]

Regarding Hawking Radiation, if a particle - antiparticle pair forms with the particle within the event horizon, wouldn't the black hole increase in mass and appear to emit an antiparticle? Are the ...
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Is there a Black Hole solution, similar to Schwarzschild solution but modified to accout for black hole mass reduction due to evaporation?

Schwarzschild solution is permanent and unchanging in time. What would happen if we modify it so to account for the change of BH mass over time due to evaporation?
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Is Bekenstein-Hawking black hole entropy the maximum bound of the entropy of a black hole?

Is the entropy $S_{BH}=\frac{c^3 A}{4Gh}$, where A is the surface area of the event horizon of a black hole, the "real" entropy of the black hole or a maximum bound of that "real" entropy?

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