The discussion centers on the existence of exact black hole solutions in non-asymptotically flat spacetimes, specifically exploring whether solutions analogous to Schwarzschild or Kerr black holes can be found in cosmological metrics such as FLRW. The scope includes theoretical considerations and references to existing literature.
Participants express differing views on the existence and relevance of exact black hole solutions in non-asymptotically flat spacetimes, indicating that multiple competing perspectives remain without a clear consensus.
Some claims depend on specific definitions of black hole solutions and the conditions of the spacetimes considered. The discussion does not resolve the mathematical complexities involved in these solutions.
The evolution of a Schwarzschild black hole in an expanding Friedman universe is described using the same coordinate patch for both geometries. Comoving and extended Kruskal coordinates are considered and compared for the cases k = 0 and k = 1. The conformal structure and some global topological aspects of the Schwarzschild-Friedman system are examined with the help of diagrams in comoving and extended Kruskal coordinates.