Superintegrable Extensions of Superintegrable Systems

A procedure to extend a superintegrable system into a new superintegrable one is systematically tested for the known systems on ${\mathbb{E}}^2$ and $\mathbb S^2$ and for a family of systems defined on constant curvature manifolds. The procedure results effective in many cases including Tremblay-Turbiner-Winternitz and three-particle Calogero systems.