Did you not argue in your paper that the DM candidate could be a WIMP (which is a linear combination of super partners)? Furthermore, it is stated in your paper that the particles have a dark U(1) charge (but there is overall charge neutrality). Puzzled…

By the way the link to Jay Alfred’s article should be:

http://ezinearticles.com/?Dark-Matter—Plasma-of-Super-Particles&id=1240357

(without the full-stop at the end … hope it works this time)

Interesting. Guess that shows that I haven’t been following axions very closely.

Robert Bast,

Anti-light is a really bad name. It can only cause confusion as it evokes anti-matter, which is a completely different phenomenon. In fact, there is an anti-particle to the photon: it’s called the photon (so yes, this means that just as an electron and a positron can annihilate with one another to produce all sorts of things, a photon can annihilate with another photon, if the pair have enough energy between them to produce anything).

I honestly don’t see how the speed of dark photons could be any different from normal photons unless they have some mass, which would cause the force to be short range, which would be something other than what Sean is proposing.

L. C.

Also, “dark photons” as imagined by Sean and others are not like negative energy that can cancel out ordinary light or energy, they are “dark” because we can’t see them (i.e., they don’t interact with ordinary matter-energy enough.)

Something you may want to consider is how fast a dark photon travels….

Sean on Nov 10th, 2008 at 12:32 pm

Actually, axions are (usually) very much cold dark matter, not warm. It’s true that their masses are small — small enough to make them hot dark matter, if they were produced in thermal equilibrium. But they’re not; they come into existence at zero momentum as part of a Bose condensate. The energy per axion is enormously smaller than the energy per CMB photon.

Well, structure formation arguments basically rule out MACHO’s, as we see the evidence of dark matter even within the CMB, which was long before any compact objects had a chance to form. The Bullet Cluster does not, because MACHO’s are just as non-interacting as the stars and galaxies: they’re few and far between, so they mostly just miss one another in a collision like that.

The difficulty with axions is that they have very low mass, which makes them a candidate for “warm” dark matter, which seems to not fit well with our current observations of structure formation. But, more observations are necessary to really say this with confidence, and perhaps the 21cm and cosmic shear observations will weigh in here to say something definitive.