New insights on marginally trapped surfaces: the hedgehog theory point of view

In this talk, we will try to argue and to show through fundamental examples that (a very huge class of) marginally trapped surfaces arise naturally from a ‘lightlike co-contact structure’, exactly in the same way as Legendrian fronts arise from a contact one (by projection of a Legendrian submanifold to the base of a Legendrian fibration), and that there is an adjunction relationship between both notions. We especially focus our interest on marginally trapped hedgehogs and study their relationships with Laguerre geometry and Brunn-Minkowski theory.