“Gravitationally only interacting dark matter” is sort of synonymous with “non-homogeneous spacetime”, or am I missing something? Ah, yes, we also need to have

“Gravitationally only interacting dark matter” is sort of synonymous with “non-homogeneous spacetime”, or am I missing something? Ah, yes, we also need to have some sort of bound energy, to balance Einstein’s equations. So, geons! https://en.wikipedia.org/wiki/Geon_(physics) https://en.wikipedia.org/wiki/Geon_(physics)