I Can black hole studies shed any light on dark matter

[BWV]

Curious if the ongoing studies of black holes at the centers of galaxies, like the Event Horizon Telescope, might provide some clues about the nature of dark matter. Tried googling this, but all I get is articles debating, mostly to the negative, the hypothesis that dark matter might be accounted for by black holes, which is not what I am asking here. I don't know how this might happen, but curious if it is possible

 

[kimbyd]

Curious if the ongoing studies of black holes at the centers of galaxies, like the Event Horizon Telescope, might provide some clues about the nature of dark matter. Tried googling this, but all I get is articles debating, mostly to the negative, the hypothesis that dark matter might be accounted for by black holes, which is not what I am asking here. I don't know how this might happen, but curious if it is possible

Probably not. Dark matter tends to not clump very readily, so that the density of dark matter near a black hole is likely to be far, far too low for it to have any impact on any measurements like this which we might wish to perform.

Our best bet for making use of black holes to measure dark matter is via dark matter annihilations: while dark matter isn't very dense, it's still more dense near dense objects, such as supermassive black holes. And if it's more dense, then dark matter annihilations, though still rare, will be more common. So looking in this direction for such annihilations is something that might be worthwhile. But it would be using completely different observation techniques than the black hole shadow images, and would have no impact on the interpretation of these images either.

 

[OCR]

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This has to be one of the "all time best" thread starter puns. . . I've ever seen. .

Can black hole studies shed any light on dark matter

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[BWV]

Thanks. It looks like dark matter annihilation are another big zero (no signs of any have been seen, right?), so it maybe excludes certain candidate particles, but little else

 

[Comeback City]

"Can black hole studies shed any light on dark matter "

This has to be one of the "all time best" thread starter puns. . . I've ever seen. .

This is a signature-worthy line...

 

[kimbyd]

Thanks. It looks like dark matter annihilation are another big zero (no signs of any have been seen, right?), so it maybe excludes certain candidate particles, but little else

There may have been some signals, but nothing definitive yet.

The difficulty is that most dark matter models tend to predict very weak signals, which means that we don't actually expect it to be easy to detect dark matter at all. The fundamental reason is simple: for dark matter to explain the astrophysical observations, it can't interact very readily either with itself or with normal matter. So it's frustrating that we haven't gotten any definitive dark matter detections yet, but patience is warranted. It could still be a few decades. This stuff is just that challenging.