Neumann and second boundary value problems for hessian and Gauß curvature flows
Nonholonomic approach of multitime maximum principle.
Non-trapping sets and Huygens principle
Non-Trapping sets and Huygens Principle
We consider the evolution of a set according to the Huygens principle: i.e. the domain at time t>0, Λt, is the set of the points whose distance from Λ is lower than t. We give some general results for this evolution, with particular care given to the behavior of the perimeter of the evoluted set as a function of time. We define a class of sets (non-trapping sets) for which the perimeter is a continuous function of t, and we give an algorithm to approximate the evolution. Finally we restrict...