Explicit solutions of the coupled Einstein-Yang-Mills-Higgs field equations representing a ’t Hooft–Polyakov–type magnetic monopole are constructed, both in and away from the Bogomolny-Prasad-Sommerfield limit. The solutions are seen to tend towards black-hole solutions as the strength of the gravitational coupling is increased, as might be expected. A careful analysis of solutions near the transition to a black hole shows that the monopole loses its non-Abelian hair as it develops a horizon. In certain cases, solutions without a horizon are seen to be unstable to gravitational collapse.

• Received 5 December 1991

DOI:https://doi.org/10.1103/PhysRevD.45.R2586