A Construction Of Singular Unitary Representations Of Reductive Lie Groups

This book is an expanded version of the Hermann Weyl Lectures given at the Institute for Advanced Study in January 1986. It outlines some of what is now known about irreducible unitary representations of real reductive groups, providing fairly complete definitions and references, and sketches (at least) of most proofs. The first half of the book is devoted to the three more or less understood constructions of such representations: parabolic induction, complementary series, and cohomological parabolic induction. This culminates in the description of all irreducible unitary representation of the general linear groups. For other groups, one expects to need a new construction, giving "unipotent representations." The latter half of the book explains the evidence for that expectation and suggests a partial definition of unipotent representations.

This book is an expanded version of the Hermann Weyl Lectures given at the Institute for Advanced Study in January 1986. It outlines some of what is now known about irreducible unitary representations of real reductive groups, providing fairly complete definitions and references, and sketches (at least) of most proofs. The first half of the book is devoted to the three more or less understood constructions of such representations: parabolic induction, complementary series, and cohomological parabolic induction. This culminates in the description of all irreducible unitary representation of the general linear groups. For other groups, one expects to need a new construction, giving "unipotent representations." The latter half of the book explains the evidence for that expectation and suggests a partial definition of unipotent representations.

This book describes the foundations of infinite-dimensional representations of real reductive Lie groups. There are three major topics. First is the Langlands classification of irreducible representations. This is done using a generalization of parabolic induction due to Zuckerman. Second is the analysis of reducibility in certain standard families of representations. Third is the formulation of Kazhdan and Lusztig's conjectural character formulas for arbitrary irreducible representations. Since the first edition was published in 1981, the Kazhdan-Lusztig conjectures have been proved, and Zuckerman's construction has been connected to unitary representations. This second edition summarizes those developments and other progress in the field.

This book is an introduction to semisimple Lie algebras. It is concise and informal, with numerous exercises and examples.

This memoir examines the basic problem of finding vanishing theorems for Harish-Chandra modules. The results of these difficult problems contribute in a meaningful way to the singular unitary representation theory of reductive groups.

This work treats a relatively singular part of the unitary dual of pseudo-orthogonal groups U(p,q;F) over F = R, C and H. These representations arise from discrete series for indefinite Stiefel manifolds U(p,q;F)/U(p - m,q,F)(2m 4p). Thanks to the duality theorem between d-module construction and Zuckerman's derived functor modules (ZDF-modules), these discrete series are naturally described in terms of ZF-modules with possibly singular parameters. The author's approach is algebraic and covers some parameters wandering outside the canonical Weyl chamber.

The past decade has seen a renewal in the close ties between mathematics and physics. The Chicago Summer Seminar on Applications of Group Theory in Physics and Mathematical Physics, held in July, 1982, was organized to bring together a broad spectrum of scientists from theoretical physics, mathematical physics, and various branches of pure and applied mathematics in order to promote interaction and an exchange of ideas and results in areas of common interest. This volume contains the papers submitted by speakers at the Seminar. The reader will find several groups of articles varying from the most abstract aspects of mathematics to a concrete phenomenological description of some models applicable to particle physics. The papers have been divided into four categories corresponding to the principal topics covered at the Seminar. This is only a rough division, and some papers overlap two or more of these categories.