The aim of this book is to give a systematic and self-contained
presentation of the Mathematical Scattering Theory within the framework
of operator theory in Hilbert space. The term Mathematical Scattering
Theory denotes that theory which is on the one hand the common
mathematical foundation of several physical scattering theories
(scattering of quantum objects, of classical waves and particles) and on
the other hand a branch of operator theory devoted to the study of the
behavior of the continuous part of perturbed operators (some authors
also use the term Abstract Scattering Theory). EBBential contributions
to the development of this theory are due to K. FRIEDRICHS, J. CooK, T.
KATo, J. M. JAuCH, S. T. KURODA, M.S. BmMAN, M.G. KREiN, L. D. FAD-
DEEV, R. LAVINE, W. 0. AMREIN, B. SIMoN, D. PEARSON, V. ENss, and
others. It seems to the authors that the theory has now reached a
sufficiently developed state that a self-contained presentation of the
topic is justified.