B Dark matter and extreme gravitational regimes

[PeterDonis]

ChatGPT

Is not a valid reference here.

 

[Dale]

Several posts about ChatGPT have been deleted. Further posts on ChatGPT will also be removed. It is not an acceptable source here.

 

[Vanadium 50]

This sound like a jumble of words, but no clear tests.

1. Suppose the LHC made semi-stable black holes. What would you do with them to tell you something about DM?
2. Homework #1 - what is the total volume of black holes (in cubic meters) you expect to make at the LHC. Show your work.
3. Homework #2: What is the total amount of DM contained in the volume of the Earth? In the volume of the previous question?
4, Given the answer to the last two questions does that cause you to rethink the answer to the first?

 

[mitchell porter]

Still, wouldn't it be cool to test dark matter via microscopic black hole evaporation?

There are models where this leaves a cosmological imprint 1 2. I'm sure their authors would agree with you!

But one should not be too excited about the mere existence of such models. A model is simply a formal statement of a possibility, and there are large numbers of possibilities, and they can't all be true. E.g. a review of inflationary models from 2013 contains over 100 distinct theories of cosmic inflation.

 

[ohwilleke]

If dark matter really lives up to it's name and truly is some form of matter, then wouldn't it feed black holes given extreme gravitational regime in a black hole?

The bulk of the theoretical and observational work being done on this question involves predictions regarding how the properties of neutron stars (which also involve extreme gravitational effects) would be different (their so called "equation of state") if they had captured significant dark matter, estimates of how much dark matter neutron stars should have absorbed, and efforts to determine if observationally neutron star properties are a better fit to the with dark matter mixed in hypothesis or the without dark matter mixed in hypothesis.

Neutron stars are more attractive than black holes for this kind of research because they are much easier to observe directly.

There are probably a few new papers every month addressing this question. See, e.g., this paper from last week entitled: "Towards Uncovering Dark Matter Effects on Neutron Star Properties: A Machine Learning Approach". There are about 123 papers in all at arXiv on this topic, using one fairly broad set of search terms.

The problem is that the anticipated differences in observable properties between neutron stars with and without dark matter are subtle, the properties of neutron stars without dark matter are hard to model and a subject of dispute, and the observations we have of neutron stars aren't terribly precise making distinguishing between the two hypotheses hard.

The best evidence of neutron star properties come from binary systems of a neutron star together with a black hole, another neutron star, or an ordinary star. But, neutron stars are, by definition, very small (on the order of a dozen miles across), which makes it tough to distinguish subtle differences in their properties at immense distances. One area of research focuses on the expected gravitational wave profile of neutron stars that collide and merge with or without significant dark matter components.

There is also work being done on how the properties of ordinary stars, especially our own Sun, should be different if they absorb a predicted quantity of dark matter. But, again, the predicted effects are subtle.