I couldn't find an answer to this question.
Suppose a dust ring around a new star contains relatively uniform dust particles.
What's the process by which they aggregate into larger bodies?
I can understand that there's a velocity distribution, so they can collide, but what makes them stick together? If they collide at low velocity, they should just bounce. If they collide at high velocity, heat energy would be released, but the fragments would just fly away.
I could see particles of opposite charge sticking together, but the result would have little charge, so it would not attract more particles.
Gravity could not become an attractant until sizable bodies could be formed.
Could it be that if a volume of space contained a large enough concentration of dust, that volume would itself have enough gravity to be an attractant?