Principal Symbol on the Heisenberg Group
摘要
We define and study the principal symbol for operators on the Heisenberg group. This involves a careful study of elliptic operators in the natural calculus of differential operators on the Heisenberg group, in particular, the proof of a priori estimates for elliptic operators. An important development here is the proof of a local Connes trace theorem in the setting of the Heisenberg group.