Black chain of pearls in 5D de Sitter spacetime

We analyze some exact chain-shaped black hole solutions in 5-dimensional spacetime. Unlike usual black string and black ring solutions, the topology of the horizons of the new solutions are neither $\mathbb{R}\times R^{2}$ nor $S^1\times S^2$ but rather like several topological spheres concatenating each other at single points. The shape of the horizon suggests the name \emph{black chain of pearls} on which each \emph{pearl} is a topological 3-sphere on the chain. In addition to the usual black hole hairs, the number of pearls can be viewed as a new hair of the black chain of pearls.