On the extension problem for semiconcave functions with fractional modulus

Paolo Albano, Vincenso Basco, Piermarco Cannarsa

Consider a locally Lipschitz function $u$ on the closure of a possibly unbounded open subset $\Omega$ of ${\mathbb{R}}^n$ with $C^{1,1}$ boundary. Suppose $u$ is semiconcave on $\overline…