Calculus on Heisenberg Manifolds

A classic treatment of the hypoelliptic calculus on Heisenberg Manifolds The classical pseudodifferential calculus is well adapted to detailed study of elliptic operators such as the Laplacian associated to the De Rham complex. This book develops a full asymptotic calculus adapted to certain second order operators which are hypoelliptic but not elliptic. The motivating example is the operator _b associated to the ∂_b-complex on a CR-manifold. Like the Laplacian, _b is a natural operator of intri