Representation Theory of Finite Groups

This book is designed to introduce the reader to the theory of semisimple Lie algebras over an algebraically closed field of characteristic 0, with emphasis on representations. A good knowledge of linear algebra (including eigenvalues, bilinear forms, euclidean spaces, and tensor products of vector spaces) is presupposed, as well as some acquaintance with the methods of abstract algebra. The first four chapters might well be read by a bright undergraduate; however, the remaining three chapters are admittedly a little more demanding. Besides being useful in many parts of mathematics and physics, the theory of semisimple Lie algebras is inherently attractive, combining as it does a certain amount of depth and a satisfying degree of completeness in its basic results. Since Jacobson's book appeared a decade ago, improvements have been made even in the classical parts of the theory. I have tried to incor- porate some of them here and to provide easier access to the subject for non-specialists. For the specialist, the following features should be noted: (1) The Jordan-Chevalley decomposition of linear transformations is emphasized, with "toral" subalgebras replacing the more traditional Cartan subalgebras in the semisimple case. (2) The conjugacy theorem for cartan subalgebras is proved (following D. J. Winter and G. D. Mostow) by elementary Lie algebra methods, avoiding the use of algebraic geometry. (3) The isomorphism theorem is proved first in an elementary way (Theorem 14.2), but later obtained again as a corollary of Serre's Theorem (18.3), which gives a presentation by generators and relations. (4) From the outset, the simple algebras of types A, B, C, D are empha- sized in the text and exercises. (5) Root systems are treated axiomatically (Chapter III), along with some of the theory of weights. (6) A conceptual approach to Weyl's character formula, based on Harish-chandra's theory of "characters" and independent of Freudenthal's multiplicity formula (22.3), is presented in 23 and 24. This is inspired by D.-N. Verma's thesis, and recent work of I. N. Bernstein, I. M. Gel'fand, S. I. Gel'fand. (7) The basic constructions in the theory of Chevalley groups are given in Chapter VII, following lecture notes of R. Steinberg. I have had to omit many standard topics (most of which I feel are better suited to a second course), e.g., cohomology, theorems of Levi and Mal'cev, theorems of Ado and Iwasawa, classification over non-algebraically closed fields, Lie algebras in prime characteristic. I hope the reader will be stirn u- lated to pursue these topics in the books and articles listed under References, especially Jacobson [1], Bourbaki [1], [2], Winter [1], Seligman [1].

表示论基础专业GTM书籍 作者：William Fulton;Joe Harris 本书是一部很受欢迎的教材，初版于1991年，至今已被Springer出版社重印5次。全书分为四部分，26章，书中主要论述李群、李代数和经典群的有限维表示，可作为大学高年级学生, 研究生及教师的教学用书。读者对象：数学及物理学专业的高年级本科生、研究生和教师。《Bulletin of the Irish Mathematical Society》评价说：“...displays a novel approach to its subject matter... genuinely informative... skillfully worked and interspersed with novel observations”；德国《数学文摘（ZENTRALBLATT MATH）》评价说：“...this textbook is an outstanding example of didactic mastery, and it serves the purpose of the series ‘Readings in Mathematics’ in a perfect manner.”。作者William Fulton当时是芝加哥大学数学系的教授，现为密西根大学数学系的教授，相交理论大家（代数几何中的重要理论）。Joe Harris是哈佛大学数学系代数几何方向的教授，前任系主任，著名的教育家。他著有多部基础教育的名著。