" So what we need is a kind of phase transition that explains why and under which circumstances the behavior of these additional fields, or particles, changes,

" So what we need is a kind of phase transition that explains why and under which circumstances the behavior of these additional fields, or particles, changes, so that we need two different sets of equations. And once you look at it this way, it’s obvious why we have not made progress on the question what dark matter is for such a long time. There’re just the wrong people working on it. It’s not a problem you can solve with particle physics and general relativity. It a problem for condensed matter physics. That’s the physics of gases, fluids, and solids and so on." See also Justin Khoury (2015) : A Dark Matter Superfluid, https://arxiv.org/abs/1507.03013 https://arxiv.org/abs/1507.03013 and Silvermann (2002): Dark Matter as a Cosmic Bose-Einstein Condensate and Possible Superfluid, https://link.springer.com/article/10.1023/A:1015934027224 https://link.springer.com/article/10.1023/A:1015934027224