J. Sahbani, PROPAGATION THEOREMS FOR SOME CLASSES OF PSEUDODIFFERENTIAL-OPERATORS, Journal of mathematical analysis and applications, 211(2), 1997, pp. 481-497
We study continuity properties of the boundary values of the resolvent
of perturbations of certain pseudo-differential operators by using re
cent versions of the conjugate operator method. Our results are optima
l on the Holder-Zygmund scale. In particular, three physical situation
s are included, namely relativistic and non-relativistic Schrodinger o
perators and the Stark effect hamiltonian. We allow a large class of p
erturbations by giving an ''optimal'' compromise between regularity an
d decay at infinity. (C) 1997 Academic Press.