Questions tagged [hawking-radiation]
Radiation seen by static observers due to quantum effects in close vicinity to a black hole, leading to the potential for eventual evaporation of black holes. Pictorially, a particle-antiparticle pair is created, with one falling through the horizon, becoming causally lost to the rest of the universe, while its neighbor escapes the gravitational potential. Originally predicted by S. Hawking in the 1970s using quantum field theory in curved spacetime.
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Why do we expect unitarity to be preserved in the black hole information paradox?
Consider the following way of describing the black hole information paradox:
Suppose we start with a pure quantum state and a black hole of mass $M$. Now we throw the pure state into the black hole ...
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Can an entity trapped past the event horizon detect getting turned into Hawking radiation?
Assuming your space ship survives engaging with the accretion disk and any spaghettification issues:
(1) I’ve read that the crew can’t tell if they’ve already crossed the event horizon. There wouldn’t ...
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What size is the smallest black hole stable at Standard temperature & pressure?
I have seen several questions regarding the size of the absolute smallest black hole, the smallest stable black hole and similar. These made me wonder; what is the smallest stable black hole if it is ...
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Can, in theory, information escape an event horizon via a specialized setup?
Can, in theory, information escape an event horizon via a specialized setup?
Specifically, send a beam of photons to be barely—just barely—inside the event horizon, then wait for hawking radiation to ...
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Entanglement entropy as the source of Bekenstein-Hawking entropy
I think I'm missing something about interpreting a black hole's entanglement entropy as the source of it's Bekenstein-Hawking entropy, and I can't find any literature on it.
So, we know that our ...
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DeSitter cosmological horizon stability?
If the universe keeps expanding at an accelerated rate (given by the cosmological constant) then the universe would approach a DeSitter spacetime where there would be a cosmological horizon that would ...
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How does the lifetime and temperature of a black hole scale with mass in higher dimenstions?
I've tried to find out how the lifetime and temperature of a black hole scale with mass in a universe with more then 3 spatial dimensions. I've spent a while trying to look up an answer to this ...
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Would this experiment potentially work for detecting whether gravitons exist?
Take a primordial black hole and measure the Hawking radiation over a large amount of time by gamma-ray detectors, as well as a Large neutrino detector.
Using theoretical calculations about the ...
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Can we infer Hawking radiation assuming the Unruh effect?
An observer near the event horizon of a black hole will experience an extremely strong gravitational field.
Due to the principle of equivalence, this observer cannot locally distinguish between this ...
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What would Hawking radiation look like from inside the event horizon?
Let’s say you fell into a rotating black hole, the inner horizon of the black hole is an infinite blue shift surface, so you should be able to observe events from the arbitrarily far future before ...
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Could any new structures be formed after the heat death of the universe?
When the universe would reach a maximal state of entropy, heat death would presumably be reached and no structures would be left after the last black hole would evaporate.
However, is this really true?...
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Could the observed GZK limit exceeding cosmic rays be due to hawking radiation?
In this question here, it was asked whether a black hole could emit protons with energies exceeding the GZK limit via Hawking radiation, the answer given was yes. So I ask, what proportion if observed ...
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Do evaporating black holes emit gravitons? [duplicate]
Do evaporating black holes emit gravitons? I know that hawking radiation consists of photons, and that for very small black holes it can also consists of sun atomic particles, but what about gravitons?...
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How exactly does Hawking radiation occur? [duplicate]
I understand some parts of the theory, I've read from here https://phys.libretexts.org/Bookshelves/Astronomy__Cosmology/Supplemental_Modules_(Astronomy_and_Cosmology)/Cosmology/Carlip/...
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Hairy black hole
I was wondering why it is said that if a black hole has hair we can measure its charge at infinity, where does this statement come from?
It doesn't seem right to me because solutions to KG equation ...
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How close would a evaporating primodial black hole be to be detected? [closed]
The power output of a black holes hawking radiation is inversely proportional to the square of it's mass. According to here, in it's final second of existence, it'll emit over 2E22 joules of energy, ...
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A question about Kerr black holes and Hawking radiation
It's a common myth that somoene falling into a black hole will see the entire history of the universe before they cross the event horizon.
With a Kerr black hole however, it's sort of true. The inner ...
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Can someone help me understand backreaction?
I was reading a paper on black-hole information loss and it mentioned backreaction. I had never heard the word before so I googled it and was surprised to find no cohesive definition that I could ...
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Where from Hawking radiation actually arise?
Where from Hawking radiation actually arise? I would like to connect the answer with the technical derivation along the lines of the original calculation by Hawking (a modern account of which is given ...
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Will Hawking radiation violate baryon number conservation around gravitating bodies other than black holes?
Numberous articles discussing a recent research paper suggest that even stars and planets will eventually radiate away their mass like hawking radiation. My question is will this violate baryon ...
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Does entropy decrease in the late universe? [duplicate]
The early universe had an entropy of $10^{88} k_B$ . This entropy does mostly come from photons, quarks and leptons and stayed constant over time, due to adiabatic expansion.
Sagittarius A* has an ...
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Bogolubov coefficients calculation
I'm studing the Hawking effect in a two dimensional Schwarzchild spacetime.
I have the modes:
$
\phi(t,r^*) = \int_\mathbb{R} \frac{d k}{(2 \pi)^{1/2}} \frac{1}{\sqrt{2 \Omega}}\left[ e^{-i(\Omega t - ...
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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 ...
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Does the interior volume of a black hole grow forever?
Recently, I was reading about a article which tells about something known as "Susskind Complexity". The article states that the interior volume of a black hole grows forever.
How/why does ...
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Superposition of Page times - is the Hawking radiation maximally mixed?
Suppose we have a black hole of mass $M$ at time $t_0$. The black hole has already been radiating Hawking radiation for some time. If no further mass is added to the black hole, suppose over half of ...
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Negative energy particle effect on observable object
A recent paper "Gravitational Pair Production and Black Hole Evaporation" (discussed in short here) says that any spacetime curvature would produce Hawking radiation, no need for event ...
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Questions about the details of deriving Hartle-Hawking state
I'm studying Hartman's "Black holes and Quantum Information" lesson(I'm a chinese so maybe I have some syntax error),and I'm confused about the Hartle-Hawking state. He says we start from ...
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Was Stephen Hawking's explanation of Hawking Radiation in "A Brief History of Time" not entirely accurate?
I've been looking into black holes and Hawking radiation recently (just on the surface level) and was reading "A Brief History in Time" by Stephen Hawking to understand the basics of ...
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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 ...
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Do black holes emit equal amounts of gravitons in addition to photons via Hawking radiation?
According to Hawking’s theory, black holes have temperatures inversely proportional to their masses and emit photons like an ideal black body. However, besides EM radiation there is also gravitational ...
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Are black holes black body? [duplicate]
I've read online that black holes are almost ideal black bodies. But for a body to be called an ideal black body it should emit all the rays of all the wavelengths but black holes don't, so how can we ...
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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 ...
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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. ...
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How are black-hole evaporations possible?
It is believed that if, $$
R \leq \frac {2Gm}{c^2} \; \;\;\;\; (1)
$$ is black hole and due to Hawking radiation it losses mass and subsequently when, $$R \geq \frac {2GM}{c^2} \;\;\;\;\;\; (2)$$ ...
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Will gravitational waves decay into photons? (and by how much?)
We know intense regions of curvature, for example near a black hole horizon, induce a flow of electromagnetic waves (and, less so, other particles). aka Hawking radiation.
By contrast, curvature in ...
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Boulware and Unruh vacuum in Schwarzschild spacetime
I am studying quantization in Schwarzschild spacetime. In class the Boulware vacuum $\left| B \right>$ has been defined using the o.n. modes $u_I(x) = \frac{1}{4\pi \sqrt{\omega}}e^{-i\omega v}$, $...
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Is there a classical description of Hawking Radiation?
Before quantum theory we knew accelerating electrons radiated electric fields. This is modelled classically (even though we know it is a quantum process emitting photons)
Similarly is there a possible ...
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On the mechanism driving Hawking Radiation
I was reading up on Hawking Radiation and here's what I read in exact words:
Physical vacuum constantly produces particle-antiparticle pairs and normally annihilate within a time given by Heisenberg'...
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Is there entropic force in a black hole?
A black hole is regarded as a thermodynamic system that has entropy. Its horizon has a temperature and corresponds to a macroscopic system, thus occupying a large number of states. In this perspective,...
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Hawking Radiation without a horizon?
I’m reading this article for a straightforward derivation of the Hawking effect https://www.researchgate.net/publication/...
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Synchrotron radiation and Hawking radiation [closed]
According to 1 answer I came across:
"There is a myth, for which Hawking himself is responsible, that
Hawking radiation is primarily made up of matter-antimatter pair
annihilation."
The ...
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How is black-body radiation affected by recoil?
In a semi-relativistic framework, which accounts for the mass of an energetic photon ($=h\nu/c^2$), a black body cannot emit a photon whose relativistic mass is greater than its own. So the higher the ...
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How are the particles constituting a black hole entangled with Hawking radiation?
On the horizon of a black hole negative energy (frequency) states of virtual particles are separated from positive energy states, while staying entangled. The negative energy states (particles or anti-...
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Fuzz Ball hypothesis of Black holes [closed]
A little help please.
How does the fuzz ball hypothesis using string theory solve the information paradox?
I have heard people who know the subject far better than me say that it in fact does but i ...
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Can an evaporating black hole emit protons with an energy beyond the GZK limit?
There are protons reaching the earth with energies that exceed what their interaction with the cosmic microwave background should allow, the so-called GZK limit.
Could an evaporating black hole emit ...
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Why is the Unruh effect observer dependent?
Why Unruh radition is observer dependent why Hawking radition is not observer dependent?
I know hawking radiation is caused by the creation of a pair partice and antiparticle in two different sides ...
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Is the vacuum spacetime around the Earth curved enough to make particles appear spontaneously?
I had a discussion with someone who said spontaneous particle creation had been seen in a lab-vacuum. I told him the spacetime around the Earth is not curved strong enough for that. But I have doubts ...
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How is Hawking radiation formally derived?
[EDITED] I'm a postdoc working in cond-mat/quant theory, and I've heard some explanations of Hawking radiation that strike me as inconsistent or silly (e.g., in terms of pair production). I'm hoping ...
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Lines of constant $r$ and $t$ in black hole Penrose diagrams
Lines of constant $r$ and $t$ are often shown on conformal (Penrose) diagrams of Minkowski space. A google search readily gives many examples such as:
Is anyone aware of a graphic that displays lines ...
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Are white holes hotter than our Sun?
A white hole is a theoretical region of spacetime and singularity that cannot be entered from the outside, although energy-matter, light and information can escape from it. In this sense, it is the ...
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