Semiclassical decay of de Sitter space into black holes with vortex-deformed horizons

We study the decay of de Sitter space into black holes whose horizons are dressed by BPS vortices of a ${\mathrm{C}\mathrm{P}}^1$ action. The process is mediated by a regular Euclidean instanton obtained as a vortex-deformed generalization of the Nariai instanton. Its Euclidean geometry has the form $S^2\times \mathrm{\Sigma }$, where $\mathrm{\Sigma }$ is a compact surface whose geometry is shaped by the vortex configuration. The resulting decay rates are controlled by a discrete topological charge, showing that matter vortices open a new topologically organized family of decay channels for de Sitter space.