On the stability of a self-similar spherical bubble of a scalar Higgs field in de Sitter space

An exact generalized discontinuous solution of the spherical-bubble type is obtained for a scalar Higgs field in de Sitter space. It is shown that the radius of such a generalized bubble evolves in accordance with one of the exact solutions to a dynamical problem considered previously for the bubble radius in the thin-wall approximation, where the bubble-wall thickness is negligible in relation to the bubble radius. Both the generalized solution and the self-similar bubble-type solution that was obtained earlier for the Higgs field in de Sitter space are studied for stability: it is shown that the former is stable, while the latter is unstable in this space. A physical interpretation of the reasons for the instability of the self-similar solution is given.