Accomodating relativity to dark matter

[Loren Booda]

If weakly acting dark matter does not interact with photons, how is special (or general) relativity applied in its case? Signaling (or lightlike geodesics) would be hard to define where there is no electromagnetic objectivity. I guess this inertness may be a problem in determining a neutrino's mass and velocity.

 

[Garth]

Dark Matter is detected by its gravitational interaction. The curvature of space-time caused by the presence of DM is detected by galaxy rotation curves, the dynamics of galaxy clusters and the lensing of distant quasars. Photons continue to travel on null-geodesics, those null-geodesics are perturbed by the said curvature of space-time, and the deflection of these null-geodesics is a measure of the presence of both seen and unseen mass, the DM is the unseen component.

Garth

 

[Loren Booda]

Thanks, Garth!

 

[ohwilleke]

Well said Garth.