Struwe's Global Compactness and energy approximation of the critical Sobolev embedding in the Heisenberg group

Giampiero Palatucci, Mirco Piccinini, Letizia Temperini

We investigate some of the effects of the lack of compactness in the critical Folland-Stein-Sobolev embedding in very general (possible non-smooth) domains, by proving via De Giorg…