Gravitational Properties of the Monopole Bag

Axionic cosmologies constitute a class of models with phenomenologically rich symmetry breaking in the early universe. In the case where monopoles are present in such a background, the axion profile may be deformed; it is possible to construct a ``monopole bag" state composed of a central monopole within a closed axion domain wall. We consider the gravitational properties of this hybrid defect, and find a both horizon-less and a black hole-like final state can result as remnants of the monopole-domain wall system after gravitational collapse for different input parameters. We demonstrate that the latter classifies as dyonic regular black hole, evading the usual singular gravitational collapse and retaining a non-trivial axionic profile through exotic electromagnetic properties of an axionic Chern-Simons term.