Current main stream theory is neutrinos must have mass. Recent paper claims its on the order of 5 to 50 eV (I've forgotten exactly). So, they must be slowed down (as well as sped up) by gravitational interaction, correct? As well as the expansion of space. Hence they must be attracted "just like" any other space dust (allowing for their high, but slowing, speed) and so wouldn't we expect some of them to be in orbit around Sag A*, the Sun or even the Earth? If this is correct, what happens to this swarm of 'cold' neutrinos?