Dark Matter at Supersonic Speed
Dark matter is the invisible scaffold that holds galaxies together. But how did it come to be? The standard answer: particles of dark matter once stopped colliding and "froze out" in the amount we see today. However, there's a trickier path — UFO, or ultra-fast freeze-out.
Here, everything is like coffee that cools down and then heats up again as you carry it through a cold corridor.