Pookadude

Taking axions for instance, they condense out of whatever feild they do that from and then start to fall twords thier mutaul center of gravity. If the area they condensed in were roughly speherical then the majority of them would have paths that cross the center of mass over and over, they would concentraite there basically. The less spherical the area they condense from then the more circular thier orbits, but if they all condense out of a perfect shpere then all thier orbits would be straight line paths through the center. I don't think they would condense out of a perfect sphere i am just pointing out that the paths of most the axions would be crossing roughly the center wich is also where the supermassive black hole is. If the black hole is perhaps orbiting the center of mass of the galaxy then it would in, from the view of axions orbiting nearby for billions of years, a much larger surface area. Maybe that explains why the dark matter doesn't seem to affect the rotation rates on galactic cores, just the suburbs, because there is a hole in the middle (cleared by the SMBH) and the effect of a feild on the inside of a sphereical shell is negligable. Just wondering about the rates of decay because I am reading about Penroses' book on CCC. Thanks again for the tolerant comments on my musings.

Thanks for the excellent replies. But, a black hole normally consumes all the avalible normal matter the rest settles into stable orbits around it, it would continously be encountering dark matter for the entirety of it's lifespan. A supermassive black hole would encounter allot of dark matter becuase it would be in highly elptical orbits around the area the black hole is in. Wouldn't it? Even realtivally tiny amounts of dark matter falling into a black hole would throw off the calculations for how quickly they evaporate?

If dark matter is some form of particle, axion, WIMP or neutralino then they would be orbiting the center of mass (primaraly thier own) of the galaxy. Thier orbits, unaffected by anything else would bring them into contact with black holes, especially the ones in the center of galaxys. While I relalise that the incident of this happening would be small, black holes would be moving and encountering dark matter like a car moving through a rainstorm, it's path would never clear it out. 10 billion years worth of encountering dark matter would make no measuarble difference? The question stems from the reported fact that we have a pretty good idea of how much normal matter was created in the big bang, and the statement I have heard in several places that this is accounted for by the visible matter, gas, dust and black holes. Also it seems to be fairly straightforward to calculate the size of a black hole that any given star would create, given it's mass and metallicity. So shouldn't black holes weigh at least a little more than the old estimates due to the dark matter they have encountered? If they don't wouldn't this be evidence against ideas of dark matter being particles? Humm don't think i understand this, if any particle that was affected by gravity encountered the event horizon would it not essentially be added to the black hole's mass?

Reading a bit about dark matter and the way we know how dark matter is not mundane matter, and that the amount of mundane matter is accounted for by other factors. The question i have is this: If dark matter makes up 5 times the mass of ordinary matter wouldn't black holes weigh signifigantly more than they do? Like 6 times what they should weigh if they are only made up of mundane matter?