Generalized BPS magnetic monopoles

Abstract

We show the existence of Bogomol'nyi-Prasad-Sommerfield (BPS) magnetic monopoles in a generalized Yang-Mills-Higgs model which is controlled by two positive functions, $g({\ensuremath{\phi}}^{a}{\ensuremath{\phi}}^{a})$ and $f({\ensuremath{\phi}}^{a}{\ensuremath{\phi}}^{a})$. This effective model, in principle, would describe the dynamics of the nonabelian fields in a chromoelectric media. We check the consistency of our generalized construction by analyzing an explicit case ruled by a parameter $\ensuremath{\beta}$. We also use the well-known spherically symmetric Ansatz to attain the corresponding self-dual equations describing the topological solutions. The overall conclusion is that the new solutions behave around the canonical one, with smaller or greater characteristic length depending on the values of $\ensuremath{\beta}$.