Differentiability of the value function on $ H^1(\Omega) $ of semilinear parabolic infinite time horizon optimal control problems under control constraints.
An abstract framework guaranteeing the continuous differentiability of local value functions on $ H^1(\Omega) $ associated with optimal stabilization problems subject to abstract semilinear parabolic equations in the presence of norm constraints on the control is established. It guarantees the local well-posedness of the associated Hamilton-Jacobi-Bellman equation in the classical sense. Examples illustrate that the assumptions imposed on the dynamical system are satisfied for practically relevant semilinear equations.