This book reflects a significant part of authors' research activity dur-
ing the last ten years. The present monograph is constructed on the
results obtained by the authors through their direct cooperation or due
to the authors separately or in cooperation with other mathematicians.
All these results fit in a unitary scheme giving the structure of this
work. The book is mainly addressed to researchers and scholars in Pure
and Applied Mathematics, Mechanics, Physics and Engineering. We are
greatly indebted to Viorica Venera Motreanu for the careful reading of
the manuscript and helpful comments on important issues. We are also
grateful to our Editors of Kluwer Academic Publishers for their
professional assistance. Our deepest thanks go to our numerous
scientific collaborators and friends, whose work was so important for
us. D. Motreanu and V. Radulescu IX Introduction The present monograph
is based on original results obtained by the authors in the last decade.
This book provides a comprehensive expo- sition of some modern topics in
nonlinear analysis with applications to the study of several classes of
boundary value problems. Our framework includes multivalued elliptic
problems with discontinuities, variational inequalities, hemivariational
inequalities and evolution problems. The treatment relies on variational
methods, monotonicity principles, topo- logical arguments and
optimization techniques. Excepting Sections 1 and 3 in Chapter 1 and
Sections 1 and 3 in Chapter 2, the material is new in comparison with
any other book, representing research topics where the authors
contributed. The outline of our work is the following.