The following result is stated: A black hole in its final state can be endowed with no exterior scalar, vector, or spin-2 meson fields. We conclude that such a black hole is not subject to the strong interactions which are mediated by meson fields such as the $\pi$, $\rho$, and $f$, and that consequently a useful definition of baryon number cannot be given for such an object.

• Received 1 November 1971

DOI:https://doi.org/10.1103/PhysRevLett.28.452