Synopses & Reviews
This work carefully examines liaison theory and deficiency modules from basic principles, taking a geometric approach. The focus is on the role of deficiency modules in algebraic geometry, particularly with respect to liaison theory, which is treated here as a subject in itself and as a tool. The structure and classification of liaison classes are explored, and a variety of ways are described in which liaison has been applied to geometric questions. The classical study of liaison via complete intersections is compared and contrasted with the relatively new study of the subject via arithmetic Gorenstein ideals.
Review
"Suitable for a graduate course in algebraic geometry...numerous discussions about the historical development, and...an ample and useful list of references to important original sources... Relations between linked schemes...are explained in great detail, with complete proofs and numerous examples. ...The book ends with a section which gives a flavour of some of the ways in which liaison theory has been applied in the literature. Many more applications and examples are spread throughout the text. They contribute to a lively and inspiring style. This book is a worthwhile addition to every algebraic geometer's library." --Mathematical Reviews "A highly specialized monograph that provides a very good introduction to contemporary research in the fields of liaison theory and deficiency modules... The author pays great attention to motivation and the geometric aspects of the theory. There are many examples through which the reader is introduced into the theory, thereby stimulating research in the field... Useful both for specialists and for postgraduate students." --EMS Newsletter
Synopsis
This book carefully examines Liaison Theory and deficiency modules from basic principles, and it describes the role played by deficiency modules in Liaison Theory. It treats Liaison Theory both as a subject in itself, exploring the structure and classification of liaison classes, and as a rich tool, describing a variety of ways in which Liaison has been applied to geometric questions. It assumes only a first course in Algebraic Geometry and Commutative Algebra, so it will be ideal for a graduate student or professional mathematician who wishes to learn the field. On the other hand, it reaches the edge of current research, and as such it will be of interest also to specialists.
Synopsis
In the fall of 1992 I was invited by Professor Changho Keem to visit Seoul National University and give a series of talks. I was asked to write a monograph based on my talks, and the result was published by the Global Analysis Research Center of that University in 1994. The monograph treated deficiency modules and liaison theory for complete intersections. Over the next several years I continually thought of improvements and additions that I would like to make to the manuscript, and at the same time my research led me in directions that gave me a fresh perspective on much of the material, especially in the direction of liaison theory. This re- sulted in a dramatic change in the focus of this manuscript, from complete intersections to Gorenstein ideals, and a substantial amount of additions and revisions. It is my hope that this book now serves not only as an introduction to a beautiful subject, but also gives the reader a glimpse at very recent developments and an idea of the direction in which liaison theory is going, at least from my perspective. One theme which I have tried to stress is the tremendous amount of geometry which lies at the heart of the subject, and the beautiful interplay between algebra and geometry. Whenever possible I have given remarks and examples to illustrate this interplay, and I have tried to phrase the results in as geometric a way as possible.