Black hole formation Definition and 21 Threads

Is there a theorem which proves that for a black hole to form, matter must gravitationally collapse to a singularity?

Black holes are everywhere in astrophysics. There are numerous discussion about how black holes look like, what happens to gas falling into black holes, how light bends around black holes, whether there is loss of information when mass or energy falls in, etc. There is thought to be a black hole...

Black holes form. An undeniable fact. Let's imagine a massive shell collapsing under its own weight (the exact composition of the mass is not important, so just imagine to be a continuous mass with zero thickness). What happens if the process of collapse evolves? The time on the inside will run...

Dear all, For a new book I'm writing I'm investigating some common misconceptions in physics. And of course, that means confronting myself with my own confusion. One thing I've never got clear in my head, and which I find hard to answer using google and my textbooks on GR, is the following: how...

Hi guys, I'm new here. I am doing my final degree project and it's hard for me to understand what this paragraph means in one of the papers that I'm reading, it's about primordial black hole formation. [Talking about a spherically density perturbation] The rarefaction wave starts at the surface...

Hello all, To my knowledge, there are still a lot of questions regarding the specifics of black hole formation. My question is in regards to formation time. I've read that the actual formation takes "less than a second" according to the equations. Does anyone know where time shows up in the...

I was reading about the pressure which is created when fermions are close of each other like in an electron gas, and I started thinking about what causes a black hole to form. Firstly, what happens when two fermions are forced to occupy the same place (and state)? By the exclusion principle I...

Can someone point me to the seminal (or any other) paper explicitly showing and proving the formation of singularities in black holes? I'd like to learn about the exact physical processes which occur during the collapse of a star into a black hole and how the progress of those physical...

I feel like this could go in quite a few of the Physics subforums (Quantum Physics, Beyond the Standard Model, Special and General Relativity, or High Energy, Nuclear, Particle Physics) instead of Astronomy and Cosmology, but hopefully this will work. This is my first question I've posed here...

I understand how the neutron stars are formed, and why the electron degeneracy pressure collapses as electrons are absorbed by protons, by photo disintegration. However, I'm struggling to grasp what happens when the gravity is large enough to overcome neutron degeneracy pressure. Apparently a...

Start with an existing black hole and an event horizon radius R at time T. Say the black hole is being "fed" an infinite series of golf balls, one after the other, which are all stamped numerically such that the current golf ball external to the event horizon is 1.0 * 10^32. See linked img...

Hi, does anyone know how much of the universes's iron or carbon has been made in supernovae that formed black holes? Is it 5, 10, 50 % of the iron currently pressent here? And, if se, do we have any idea how much of the average stars content gets traped in the BH versus the mass of the...

This scenario is described by Lenard Susskind in a lecture on general relativity starting at time stamp 44:23 in the following video. The scenario is that a spherical shell of radiation is directed inward to a point. The shell contains enough energy to form a black hole. He states that...

How can be the black holes formed in proton -proton collision

When a massive star dies, you either get a neutron star, or a black hole. From my lecture, neutron star are extremely hot object, with temperature around 10E11 to 10E12 kelvin. I'd assume black hole created from a similar process with just more mass, wouldn't have temperature any lower...

I just recently came across this idea, outlined in http://arxiv.org/abs/1005.3497" ). I've looked for some discussion here, but couldn't find any, so I thought I'd start one (if I missed some previous discussion, I'd appreciate a link). The basic idea is simple: to probe transplanckian...

Suppose that we have an ellipsoidal shell of particles, all initially at rest in some frame, which are going to collapse to form a black hole. Since the cloud has a nonvanishing mass quadrupole moment Q, and Q is varying with time, we should get gravitational radiation. First let's consider...

. They understand the classical Schwarzschild radius argument for black hole formation. They have bare rudiments of special and general rel. I sound like an idiot saying "there's this anti-gravity" force that kicks in when the collapsing system gets really big. Any help?

Could the process of star formation in a collapsing gas cloud transform the process of virialisation and ultimately promote the formation of a central black hole? Consider the following idealised and oversimplified scenario. Suppose a gas cloud massive enough to generate vast numbers of...

This question involves the following statement in Schutz, A First Course in GR, but you don't need to have a copy to answer it. He says that in the formation of a black hole from a supernova explosion, we should expect gravity waves of amplitude M/R, where M is the mass and R is the distance...

Hi, I'm an amateur cosmologist/physicist and I was hoping that someone more well-versed in these areas may be able to comment on this idea that I have. Assuming space-time is quanitized and the universe is limited to 3 spatial dimensions (as in Loop Quantum Gravity), has any research been...