Dark Matter

[DeiRenDopa]

Generally "WIMP" refers to a currently unknown particle with a much larger mass than neutrinos. But your point is well-taken - neutrinos might have been DM. They aren't, because they aren't heavy enough to account for the data, but it goes to show that DM need not be so mysterious or surprising.

One interesting and still viable option are axions.

(bold added)

There's another, related, possibly more powerful, reason for ruling out neutrinos (at least the neutrinos we know of, and as a significant component of DM): neutrinos are hot dark matter, and the astronomical observations overwhelming point to the existence of cold dark matter.

The distinction may seem impossibly esoteric, but it is, nonetheless, relatively straight-forward to test (via well-formulated hypotheses and independently verified astronomical observations, etc), and the results are quite clear-cut: the DM that astronomers 'see' is CDM, not HDM, or even WDM (warm dark matter).

One way to understand this is as follows: if DM is hot, it doesn't hang around long enough to be able to form (self-gravitating) spherical shapes (or slightly bent-out-of-shape spherical shapes) with the characteristic sizes that the DM galaxy halos and clusters of galaxies* are inferred to have.

* there's more to it - no surprise, right? - but at the '2nd level' ...

 

[arthwollipot]

WIMPs sounds better that GOIPs (gravity only interacting partciles)

Yeah - being called a WIMP is bad enough, but it's better than being called a GOIP.

"You're such a goip."