> I have heard it is plausible that Dark Matter is merely another particle that fits in the standard model. I've heard it plausible that Dark Energy is e.g. a W

> I have heard it is plausible that Dark Matter is merely another particle that fits in the standard model. I've heard it plausible that Dark Energy is e.g. a WIMP or other new particle in the standard model. Whoever told you that was getting dark matter and dark energy mixed up. Dark matter could be "another particle", possibly a sterile neutrino: https://en.wikipedia.org/wiki/Sterile_neutrino#Sterile_neutrinos_as_dark_matter https://en.wikipedia.org/wiki/Sterile_neutrino#Sterile_neutr... Dark energy however is definitely something else. WIMPs in particular are hypothetical dark matter particles: https://en.wikipedia.org/wiki/Weakly_interacting_massive_particles https://en.wikipedia.org/wiki/Weakly_interacting_massive_par...