The annual Operator Theory conferences in Timigoara are conceived as a
means to promote cooperation and exchange of in- formation between
specialists in all areas of Operator Theory. The present volume consist
of papers contributed by the partici- pants of the 1981 Conference.
Since many of these papers contain results on the invariant subspace
problem or are related to the role of invariant subspaces in the study
of operators or operator systems, we thought it appropiate to mention
this in the title of the volume, though the "other topics" have a wide
range. As in past years, special sessions concerning other fields of
Functio- nal Analysis were organized at the 1981 Conference, but contri-
butions to these sessions are not included in the present volume. The
research contracts of the Department of Mathematics of INCREST with the
National Council for Sciences and Technology of Romaliia provided the
means for developping the research activity in Functional Analysis;
these contracts constitute the generous framework for these meetings. We
want also to acknowledge the support of INCREST and the excelent
organizing job done by our host - University of Timigoa- ra-. Professor
Dumitru Gagpar and Professor Mircea Reghig are among those people in
Timigoara who contributed in an essential way to the success of the
meeting.