The trace problem for vector fields satisfying Hörmander's condition

Abstract

Trace theorems are proved for non-isotropic Sobolev and $L^p$-Lipschitz spaces defined by vector fields satisfying Hörmander's bracket condition of order 2. It is shown that the loss of regularity by traces is the same as in the classical case.

Published in Mathematische Zeitschrift 231 (1999), no. 1, 103-122