Solvability of dissipative second order left-invariant differential operators on the Heisenberg group
arXiv:math/0307002
Abstract
We prove local solvability for large classes of operators of the form where the are left-invariant vector fields on the Heisenberg group satisfying the commutation relations for , and where is a complex symmetric matrix with semi-definite real part. Our results widely extend all of the results for the case of non-real, semi-definite matrices known to date, in particular those obtained recently jointly with F. Ricci under Sjöstrand's cone condition.
36 pages