  Black holes are important astrophysical objects describing an end state of
stellar evolution, which are observed frequently. There are theoretical
predictions that Kerr black holes with high spins expel magnetic fields.
However, Kerr black holes are pure vacuum solutions, which do not include
accretion disks, and additionally previous investigations are mainly limited to
weak magnetic fields. We prove for the first time in full general relativity
that generic rapidly spinning black holes including those deformed by accretion
disks still expel even strong magnetic fields. Analogously to a similar
property of superconductors, this is called Meissner effect.
