Are there any EXACT solutions similar to Schwarzschild or Kerr in a spacetime which is not asymptotically flat; e.g. FLRW or other cosmological metrics? I am already familiar with the "Swiss cheese" approximations.
If you have an infinite universe you will have an infinite number of 15 Gly regions of approximately the same composition. An infinite number will be very, very similar to the one we inhabit. There will be some where a close, if not exact, copy of you and I exist. It may well be true...
Not sure if I should post this question here or in the Materials & Chemical Engineering forum but I will give it a try.
If I were to take several modern items, let's say an iPhone, a set of chrome vanadium steel wrenches and a stainless steel/titanium Smith & Wesson revolver and bury them...