[mirimir]

TFA doesn't mention recent evidence that primordial black holes are rare. It also doesn't address issues around condensation of dark matter. That is, two dark-matter objects can't collide, because they'll just pass through each other.

[the8472]

They can still get rid of momentum in N-body interactions via gravitational waves (N>=2) or by transferring to it to another body (N>2). The question is whether those mechanisms are significant enough to lead to compact bodies.

[mirimir]

Thanks.

Is it generally accepted that the large-scale structure of the universe (presumably including dark matter) reflects quantum-scale structure before inflation?

[canjobear]

Dark matter objects interact with regular matter only via gravity. But the article seems to suggest that it might interact with itself by some other force, which may allow for "collision":

"Dark matter seems to interact with normal matter only through gravity, but, based on the way known particles interact, theorists think it’s possible that dark matter might also interact with itself. "