الصفحة 1
الصفحة 1
Notes on Coxeter Transformations and the McKay Correspondence
One of the beautiful results in the representation theory of the finite groups is McKay's theorem on a correspondence between representations of the binary polyhedral group of SU(2) and vertices of an extended simply-laced Dynkin diagram. The Coxeter transformation is the main tool in the proof of the McKay correspondence, and is closely interrelated with the Cartan matrix and Poincaré series. The Coxeter functors constructed by Bernstein, Gelfand and Ponomarev plays a distinguished role in the representation theory of quivers.
Groupes et algèbres de Lie : Chapitres 4 à 6 = Lie groups and algebras : Chapters 4 to 6
Nicolas BOURBAKI's Elements of Mathematics aim to provide a rigorous, systematic presentation without prerequisites of mathematics from their foundations.This third volume of the Book on Groups and Lie Algebras, ninth Book of the treatise, is devoted to the structures of root systems , Coxeter groups and Tits systems, which appear naturally in the study of analytic or algebraic Lie groups
Combinatorics of Coxeter Groups
Coxeter groups are of central importance in several areas of algebra, geometry, and combinatorics. This clear and rigorous exposition focuses on the combinatorial aspects of Coxeter groups, such as reduced expressions, partial order of group elements, enumeration, associated graphs and combinatorial cell complexes, and connections with combinatorial representation theory. While Coxeter groups have already been exposited from algebraic and geometric perspectives, this text is the first one to focus mainly on the combinatorial aspects of Coxeter groups. The first part of the book provides a self-contained introduction to combinatorial Coxeter group theory. The emphasis here is on the combinatorics of reduced decompositions, Bruhat order, weak order, and some aspects of root systems. The second part deals with more advanced topics, such as Kazhdan-Lusztig polynomials and representations, enumeration, and combinatorial descriptions of the classical finite and affine Weyl groups. A wide variety of exercises, ranging from easy to quite difficult are also included.
Matematica e cultura 2005 = Mathematics and culture 2005
E si parla di arte; oltre che di Pizzinato, di Pollock, grazie alla collaborazione della Guggenheim Collection di Venezia.E si parla di architettura, dalla topologia ai progetti di Ghery e di Renzo Piano.E di modelli matematici per la lotta contro il cancro, contro l’AIDS.Di come la matematica può aiutare a prevenire e intervenire. E si parla di matematica della guerra e di come la matematica possa aiutare a proteggere l’ambiente. Nel gennaio 2005, scrivendo queste parole, diventa di grande e drammatica attualità l’utilizzo dei modelli matematici per la meteorologia. Prevedere per salvare.
Buildings : Theory and Applications
This book treats Jacques Tits's beautiful theory of buildings, making that theory accessible to readers with minimal background. It includes all the material of the earlier book Buildings by the second-named author, published by Springer-Verlag in 1989, which gave an introduction to buildings from the classical (simplicial) point of view. This new book also includes two other approaches to buildings, which nicely complement the simplicial approach: On the one hand, buildings may be viewed as abstract sets of chambers with a Weyl-group-valued distance function; this point of view has become increasingly important in the theory and applications of buildings. On the other hand, buildings may be viewed as metric spaces. Beginners can still use parts of the new book as a friendly introduction to buildings, but the book also contains valuable material for the active researcher.
