Inserted: 28 sep 2010
Last Updated: 4 aug 2015
Journal: Ann. Scuola Norm. Sup. Pisa Cl. Sci.
Using the notion of h-subdifferential, we characterize both first and second order differentiability of h-convex functions in stratified groups. We show that Aleksandrov's second order differentiability of h-convex functions is equivalent to a suitable differentiability of their horizontal gradient.