Questions tagged [black-holes]
A black hole is a region of spacetime from which nothing can escape. More formally, the future light cone of any observer within the black hole is completely contained in the black hole, and the black hole region is not within the past light cone of any observer that goes to spatial infinity in an infinite amount of time.
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Does a horizon-based compression mapping violate semiclassical GR if total information is conserved but representation changes? [closed]
This is a purely technical question regarding horizons and information representation, not a model proposal.
Assume a system with two coexisting representations of information:
(i) a locally readable, ...
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Would a photon with a wavelength equal to the schwarzschild radius of a charged black hole scatter off the black hole?
Do photons with long wavelengths scatter off charged black holes and could we find such photons and distinguish them from other photons in space by their wavelengths?
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The relationship between black holes and white holes? [closed]
Model of the Temporal Laws of Black and White Holes
Author: Yacine Allache – Student in the Second Year of Baccalaureate
Note:
This model does not aim to be a verified scientific theory, but rather a ...
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Does GR predict this empirical link between radiated GW energy and final Kerr thermodynamics in BBH mergers?
I am analysing GWTC-1/2/3 binary black hole mergers using only the published parameters (initial masses/spins, final mass/spin, radiated GW energy).
Across 40 well-measured BBH events, I notice that ...
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Is it possible that space can exist without time in some extreme cases like inside a black hole or before the Big Bang?
Is it possible that space can exist without time in some extreme cases like inside a black hole or before the Big Bang?
Clarification (from space without time) I for example mean that the axis of time ...
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Scientific benefits of a small primordial black hole [closed]
If a small primordial black hole M=(1E11Kg-1E12Kg) were to wander into our solar system spewing out hawking radiation, what scientific benefits would receive by observing it?
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Asymptotic flatness of Kerr metric
I am following Geometry and physics of Black Holes by Eric Gourgoulhon https://share.google/zA50kChCq9PE75bnT
At page#322-323 he said for Boyer Lindquist metric
The spacetime has two asymptotically ...
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In a stationary, asymptotically flat spacetime, when does a Killing horizon coincide with the event horizon?
In general relativity, the black hole region (B) of an asymptotically flat spacetime $M,g$ is defined globally as
$$
B := M \setminus J^-(\mathscr I^+),
$$
and the (future) event horizon is its ...
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If quark stars were to exist, would we expect them to demonstrate more extreme forms of the behaviours observed from neutron stars?
For example - would we expect quark stars to have intense magnetic fields in the same way neutron stars do, that could then lead to them becoming pulsars?
Or would the breakdown of hadrons into quark ...
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Can the electron beat the photon in this race?
I have two possible scenarios and I wonder whether the electron and arrive before the photon in either of them.
Scenario 1: There is an emitter at A, and a reciever at B. Let the midpooint of AB be C.
...
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Shockwave as a source in Penrose diagram
While reading some papers as a master student I came across some ideas when analysing certain spacetimes of introducing a shockwave at the null infinities as a matter source. Can someone explain what ...
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If either existed, how would the process of a quark star transforming into a strange star alter the physical size of the object?
I'll admit this is actually several questions rolled into one...
1 - Assuming I understand the theory behind quark stars correctly, only a certain number of up and down quarks can occupy the same ...
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Is Big Crunch time reversed Big Bang - before it there would be formed black or white holes?
Big Crunch is often presented as time reversed Big Bang, e.g. https://www.sciencealert.com/physicists-predict-when-the-universe-will-end-in-a-reverse-big-bang
I wanted to ask how true is it especially ...
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Is it statistically likely that a single black hole made of dark matter exists in the observable universe?
This popular article considers the question whether dark matter could be concentrated with a high enough local density to collapse into a black hole. It confidently concludes that the answer is "...
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Would you see the entire past history of the universe when falling into a charged/rotating black hole?
Would you see the entire past history of the universe when falling into a charged/rotating black hole as you approached the inner event horizon?
I’ve read multiple sources here that contradict each ...
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