Before dark matter, dark light (maybe)

Earlier today Liang and Caldwell floated to their university press yet another Cold Dark Matter candidate: the now-baryonic cooper-pair of a lost massless fermion. Which Dartmouth needs explain. I'll take a crack at this too.

Dark Matter is dark because it doesn't interact with light, nor (as far as we know) with charge. Matter only does it attract, and that by the weakest interaction: gravity. At least the neutrino can, one-in-a-quintillion, hit a particle: our detectors count on this. We are also not talking about hydrogen clouds, like "Eos" lately, which interact as hydrogen usually does such as present its transparent annoyances for us. Dark Matter is deduced only for how it spins up entire galaxies. Thus opening up unCDM theories like Milgrom's MOND (at least a testable one, if defunct now) and the scalar field.

The new paper invokes the Cooper Pair of electrons. At sufficiently-low temperatures, electron pairs go superconductive: they pass on charge without resisting - without interacting. Suppose, this Cooper of authors suppose, dark-matter express the Cooper Pair of something else before it.

The dark predecessor would be analogous to a dark light: massless-with-energy. Light happens to be a boson in electromagnetism, but massive bosons exist like the W and Z in electroweak and that darn Higgs. The dark light would be a massless fermion, in reverse - I assume lepton if it's like the electron. On transition (paired-up), that energy would be preserved (in double) as the mass: now subject to the Special Relativity, c^2/E. (Warning: Caldwell himself in the pressrelease is muddying his own paper when he says "near-massless". This is a rare occasion when the presser presents the paper more accurately than does the interview-subject himself.)

The authors propose how to test this theory. Testable theories are always good, like those theories which propose a charge to Dark Matter. Even not finding a charge - which hasn't been found - crosses a theory off the list. Dark Matter if by pair won't express charge to observers but could have done so at the Bang, so would be visible in the CMB.