Resonant excitations of the 't Hooft-Polyakov monopole -: art. no. 151802

The spherically symmetric magnetic monopole in an SU(2) gauge theory coupled to a massless Higgs field is shown to possess an infinite number of resonances or quasinormal modes. These modes are eigenfunctions of the isospin 1 perturbation equations with complex eigenvalues, E-n=omega(n)-igamma(n), satisfying the outgoing radiation condition. For n-->infinity, their frequencies omega(n) approach the mass of the vector boson, M-W, while their lifetimes 1/gamma(n) tend to infinity. The response of the monopole to an arbitrary initial perturbation is largely determined by these resonant modes, whose collective effect leads to the formation of a long living breatherlike excitation with an amplitude decaying at late times as t(-5/6).