Dark Matter: Interacting Particles & Gravitational Forces

[someGorilla]

I didn't know where to post this. Astrophysics? Particle physics?
I know very little of dark matter. I've read that it's sometimes supposed to interact only gravitationally, and also that weakly interacting particles have been proposed as its constituents. Is there a reason why they should participate in weak interactions, other than the hope to be able to detect them?

 

[Chronos]

There is good reason to believe DM is a WIMP, like a neutrino, but, somewhat less interactive. Neutrinos can pass through light years of lead without a collision.

 

[twofish-quant]

I didn't know where to post this. Astrophysics? Particle physics?
I know very little of dark matter. I've read that it's sometimes supposed to interact only gravitationally, and also that weakly interacting particles have been proposed as its constituents. Is there a reason why they should participate in weak interactions, other than the hope to be able to detect them?

The cosmological data just says that dark matter has to be "cold" which means that it's likely to involve massive particles. The "weak" part comes from certain possible particle candidates, but there are cold dark matter candidates that aren't WIMPS, namely axions, shadow matter, and some other candidates.

http://arxiv.org/abs/0803.4196

 

[Chalnoth]

I didn't know where to post this. Astrophysics? Particle physics?
I know very little of dark matter. I've read that it's sometimes supposed to interact only gravitationally, and also that weakly interacting particles have been proposed as its constituents. Is there a reason why they should participate in weak interactions, other than the hope to be able to detect them?

The W in WIMP doesn't necessarily mean the weak nuclear force specifically. All it means is that they don't interact much with normal matter or each other. But yes, weak-force interacting dark matter is one common model for dark matter.