Sorry, I cannot find a link, but feel free to ask what does not make sense. As for the stable time loop, I’m not sure that it is always possible to find, given that you apparently want to fix both initial and final conditions of a hyperbolic PDE, unless I misunderstand what is involved in constructing such a loop.
Solely on the uniqueness of the metric in GR.
Do you have a link to a better explanation?
Also, can you explain how this could be used to find a stable time loop?
Sorry, I cannot find a link, but feel free to ask what does not make sense. As for the stable time loop, I’m not sure that it is always possible to find, given that you apparently want to fix both initial and final conditions of a hyperbolic PDE, unless I misunderstand what is involved in constructing such a loop.