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Questions tagged [gravitational-collapse]

Use for questions related to the creation/possibility of black holes in a certain situation, singularities, the contraction of an astronomical object due to its own gravity, and the re-collapse of our universe. Do not use for questions relating to normal gravitational attraction.

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How can dark matter collapse without collisions or radiation?

I understand that dark matter does not collapse into dense objects like stars apparently because it is non-interacting or radiating and thus cannot lose energy as it collapses. However why then does ...
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Throwing a micro black hole into the sun: does it collapse into a black hole or does it result in a supernova?

What do we know about accretion rates of micro black holes? Suppose a relative small black hole (mass about $10^9$ kilograms) would be thrown into the sun. Eventually this black hole will swallow all ...
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1answer
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Is it possible for a black hole to form for an observer at spatial infinity? [duplicate]

To my knowledge if you calculate the coordinate time (time experienced by an observer at spatial infinity) it takes an infinite amount of time for an object to fall past the horizon of a Schwarzschild ...
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Numerical relativity resources - Adaptive Mesh Refinement

I have, in the past few months, been studying numerical relativity, specifically the problem of spherical collapse of a scalar field as studied by Choptuik. I have also taken a look at some books that ...
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3answers
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How does gravity cause nuclear fusion in stars?

I am a bit confused regarding the nuclear fusion that occurs during star formation. For example, suppose there is a huge hydrogen cloud. It gets more mass and therefore pulls in more and more hydrogen,...
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0answers
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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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4answers
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What happens during gravitational collapse to cause the formation of a star?

I know that stars are formed from dense regions in large gas clouds. I know that when gravity causes the mass of the clump to get so big that its internal pressure can't sustain it, it collapses and ...
12
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1answer
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What happens to atoms inside a black hole?

Black holes have very high gravitational force that tends to crush everything. So as we know atoms in a molecule have inter-atomic spacing between them and further electrons also revolve at a certain ...
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2answers
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Questions about the Jeans length

I have a couple of questions about the Jeans length. Suppose the universe has a homogeneous energy density, except there's a spherical region that is overdense. I understand that if the region is ...
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1answer
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Do galaxies have a halo of neutrinos and cosmic microwave background?

If virial arguments as in "How can dark matter collapse without collisions or radiation?" allow concluding that dark matter could collapse to galactic halos purely gravitationally, then is this true ...
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4answers
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White Holes and Time-Reversed Oppenheimer-Snyder collapse

So, the canned explanation that I always hear about why the white hole solution of the extended Schwarzschild solution is non-physical is that "The matter distribution cuts off the white hole solution....
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1answer
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Free fall time of collapsing non-rotating star in GR according to a distant observer

Suppose a star with a spherically symmetric mass distribution, mass $2\cdot M_{sun}$ and initial radius $R$, undergoes a gravitational collapse after all gas pressure has vanished. The final radius ...
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So gravity turns things round

It makes sense, since gravity tends to push the surface of a body towards it's center. Unless I'm mistaken, everything with mass has it's own gravity, every atom and for instance, our own bodies ...
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2answers
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Gravity/Energy relationship

I understand that gravity is not energy, but is force, but my question revolves around if the presence of gravity in the universe results in a continuous amount of energy, from gravity-induced ...