Is there a maximum mass for a black hole?

hubble_bubble

Does anyone know if there are any detections of waves from around a black hole and what frequency range they are at?

Chronos

There is no known link between dark matter and black hole mass [re: Supermassive black holes do not correlate with dark matter halos of galaxies http://arxiv.org/abs/1101.4650]. It is also unlikely dark matter is a significant contributor to black hole mass because, unlike baryonic matter, it is essentially collisionless. Baryonic matter is slowed by collisions with other baryonic matter allowing it to shed angular moment and be captured by local gravitational wells [like black holes]. Ingesting large amounts of dark matter would also interfere with galaxy formation via a process called runaway accretion.

hubble_bubble

I have just looked up this article about quantum gravity.

http://www.sciencedaily.com/releases...0212075309.htm

If the speed of light is frequency dependent then this could explain the position of the halo.

hubble_bubble

I'll get back to you on that I have just had some very interesting thoughts.

hubble_bubble

"We conclude that black holes do not correlate directly with dark matter. They do not correlate with galaxy disks, either. Therefore black holes coevolve only with bulges."

This implies rotational velocity as the bulge will form around a rotating black hole, presumably with significant velocity. Also accumulating an ergosphere where time and space behave in peculiar ways.

hubble_bubble

One definite link is that dark matter does not cluster near a black hole. This would distort the galaxy it inhabits. I see your point though. They do say that it is "unless they contain a bulge". In this scenario the correlation has to be explained somehow.

Just a follow up I do not believe that the dark matter contributes to the mass of a black hole. I am just trying to work out how they are linked under certain conditions.

hubble_bubble

just one fly in the ointment. If the event horizon stops anything at light speed or less escape the black hole how does gravity itself have an influence outside the EH. It travels at the sped of light. I know that this sounds like a very silly question to ask as it is self referencing, but that is a force that travels at the speed of light that violates its own bounds. We do not even know what gravity is but there could be a case for arguing that is should trap everything including itself.

Drakkith

Since that article is over 11 years old and I've never heard of this before, I'm going to assume that no correlation has been observed yet. Nor do I understand how this could possibly explain the position of the halo.

I really don't think the rotation of the black hole has anything to do with the velocity of the bulge. The effect of the black hole's rotation just doesn't extend far enough out to do anything like this to my knowledge.

Gravity is in the geometry of spacetime, it is not something that has to "get out" of anything. Gravity WAVES travel at the speed of light, but gravity, meaning the geometry of spacetime, acts instantly. It is only the change in spacetime that moves at c.

Chronos

See http://curious.astro.cornell.edu/que...hp?number=264/

hubble_bubble

Thanks for the link. Interesting.

hubble_bubble

I take your points. I have to say though that the prograde and retrograde photon orbits have set distances that can be calculated for a Scwarzchild black hole. For Kerr black holes the spherical orbits can also be described. These distances are proportional. Why then can this not extend further. We have gravity amplification in effect and an enormous mass. Since theoretically gravity extends to infinity the diminishing force has a curve plotted against mass and distance. In the normal universe outside the event horizon I would expect this to behave differently than when a black hole is involved.

Drakkith

You can extend it further. It just has negligible effect due to the vast distances between objects in space. And I don't know what you mean by "gravity amplification", as such a thing does not exist. Gravity behaves no differently near a black hole than it does near any other object.

hubble_bubble

On a related note work has been done on halo size and truncation.

http://www.google.co.uk/url?sa=t&rct...1LLKDjej9q1YPg

hubble_bubble

Within the event horizon I would say that gravity is definitely amplified. Past the point of no return. BTW what mass would produce a Swarzchild radius equal to the Planck length and also to Planck length cubed?

hubble_bubble

I am currently studying this.

http://www.google.co.uk/url?sa=t&rct...fZGFoUhzRrSDtQ

It ties in with some calculations I was working on. I didn't believe the results I obtained as they violated relativity, until I read this.

Drakkith

Then you are incorrect. Gravity is not amplified within the event horizon according to current theory.

hubble_bubble

If you study the article in the link in #83 then this is what happens. Also mass is increased as if out of nowhere which is what I had found and didn't believe. This research ties cold dark matter to black holes.