Quantum mechanics explains these ultra-light particles as “fuzzy” because they exhibit wave-like behavior
How’s that different from any other particle? Aren’t they all waves in quantum fields?
I don’t know if this helps but starting at roughly 39:00 of this Fermilabs lecture the lecturer mentions that lighter the dark matter particle is more wave like it behaves and so you have to imagine like a “fluid” of waves that can be macroscopic.
Ok, I just gotta say that watching this type of talk here, puts my mind at rest that the Fediverse is going to be alright. That we are in the right place.