Generalized differentiability of the metric projection operator in Hilbert spaces

In this paper, we study the generalized differentiability of the metric projection operator in Hilbert spaces. We find exact expressions for Mordukhovich derivatives for the metric projection operator onto closed balls in Hilbert spaces and positive cones in Euclidean spaces and in real Hilbert space l2. We investigate the connections between Frechet differentiability, Gateaux directional differentiability and the Mordukhovich derivatives of the metric projection operator in Hilbert spaces.