So I have been thinking. Light gets redshifted because of the cosmological expansion of the Universe. This would mean that other, material particles, should get "cosmologically redshifted" as well right? So, for example, if an electron were flying towards us from some distant galaxy (and we neglected all other effects), would this electron lose energy as it moved towards us simply due to the expansion of the universe? What is the rate at which it loses energy? It's been too long since I've taken a cosmology class for me to do this calculation myself with any confidence of correctness.