A related article about 4d black holes of unusual shapes: https://www.quantamagazine.org/mathematicians-find-an-infinity-of-possible-black-hole-shapes-20230124

A related article about 4d black holes of unusual shapes: https://www.quantamagazine.org/mathematicians-find-an-infinity-of-possible-black-hole-shapes-20230124/ https://www.quantamagazine.org/mathematicians-find-an-infini... One day someone will consider GR with multiple timelike dimensions, and maybe will even stop assuming that the spacetime topology has to be exactly the same everywhere.