Have there been studies of "old photons" to see just how constant things like Planck constant has been?
How can we know the density of particles in interstellar or intergalactic space and could that density form dark matter?
When two galaxies with dark matter halos merge do they provide evidence for fermionic or bosonic dark matter?
Why are WIMP dark matter particles, if Majorana-like, expected to annihilate upon contact? But not neutrinos?
Only top scored, non community-wiki answers of a minimum length are eligible