Eigenstate theory says in a nutshell for even the smallest of actions/movements/events occurring in the present, an infinite (or seemingly so) top-level universes are created. If that is true and there were a way to move between eigenstates, it may be possible to move to a given point in the past.
This does not work to go to the future as eigenstates are the product of events, and as such don't exist until events happen.