So far as I know attempts to detect new particle that responsible for the nature of dark matter/energy are not successful. And there are reasonable explanation for this, like energy levels we can get access on earth, sensitivity of detectors and so on.
Are there another views on what dark matter/energy is?
Are there any other theories that explains movements of galaxies, universe clustering and other observations (that lead us to assume dark matter existence) as an exotic states of space-time? And these states do not let matter within it to interacts with the rest of the universe in electromagnetic way (it affects gravity field only)?
For example, GR solutions allow existence of CTC. Causality principle still holds if CTC space-time is not reachable from the outside, i.e. it enclosed in a singularity shell that stops continuation of the smooth solutions of space-time trajectory.
I am not trying to say that dark matter is a clusters of CTCs. My question is: what are alternative explanation of observed phenomenon that is attributed to "dark matter particle"? Is view of dark matter/energy as an exotic state of space-time have obvious flaws?