Why can't dark matter halos collapse to be the same size as the visible parts of galaxies?
A) Dark matter can't dissipate its energy through collisions.
B) Dark matter is mostly made of mini-black holes.
C) Dark matter has much more angular momentum.
D) Dark matter annihilates when it begins to get that dense.
E) Dark matter particles are too large to collapse that much.

Question

Quizplus · Accepted Answer

Dark matter cannot dissipate energy through collisions like normal matter, which prevents it from collapsing to form dense structures like the visible parts of galaxies.

Why Can't Dark Matter Halos Collapse to Be the Same