The term "factors" denotes simple von Neumann algebras. In 1982, Vaughan Jones started the study of subfactors when he gave a natural definition of the index of a subfactor of a particular kind of factor. He discovered some remarkable restrictions on the possible values of this index and some totally unexpected connections with knot theory. Since then many examples have been discovered. A tractable large class of subfactors, the so-called amenable ones, has been completely classified. The range of related areas has continued to grow, with the latest addition being the theory of superselection sectors. Professor Sorin Popa has been involved in this subject almost from the beginning and is the world's leading expert on "type II factors". This project will support an NSF-CBMS Regional Research Conference in the Mathematical Sciences on Classification of Amenable Subfactors and Related Topics to be held August 24 - 28, 1993, at the University of California, Santa Cruz. Professor Sorin Popa will be the principal lecturer. The conference is expected to draw participants from the west coast of the U.S. and Canada, including UC Berkeley, UCLA, U Nevada at Reno, and the Universities of Victoria and Vancouver. To stimulate interest and activity in mathematical research, the National Science Foundation each year supports a number of NSF-CBMS Regional Research Conferences in the Mathematical Sciences. Each five-day conference features a distinguished lecturer who delivers ten lectures on a topic on important current research in one sharply focused area of the mathematical sciences. The lecturer subsequently prepares an expository monograph based upon these lectures, which is normally published by the American Mathematical Society or the Society for Industrial and Applied Mathematics, or jointly by the American Statistical Association and the Institute of Mathematical Statistics. Certain features differentiate these conferences from typical research conferences. These are: (1) Focus on a single important and timely area of research by a leading practitioner, (2) Continued effect and local stimulation through regional emphasis, (3) Panel review for quality, breadth, and timeliness, and (4) Published monographs for a wider audience.
