Celebrating two old friends: Juan Manfredi and the p-Laplacian

As a young Ph.D. student, the first nonlinear operator I met was the p-Laplacean; later on, the first visitor I invited to Parma was Juan Manfredi (in 1997, if I remember correctly). And it is definitely not by chance the two things are related. This talk is the occasion to celebrate both of them, with some recent regularity results coming form nonlinear potential theory.