G. Lusztig, Massachusetts Institute of Technology, Cambridge, MA

Hecke Algebras with Unequal Parameters

Expected publication date is March 6, 2003

Description
Hecke algebras arise in representation theory as endomorphism algebras of induced representations. One of the most important classes of Hecke algebras is related to representations of reductive algebraic groups over p-adic or finite fields. In 1979, in the simplest (equal parameter) case of such Hecke algebras, Kazhdan and Lusztig discovered a particular basis (the KL-basis) in a Hecke algebra, which is very important in studying relations between representation theory and geometry of the corresponding flag varieties. It turned out that the elements of the KL-basis also possess very interesting combinatorial properties.

In the present book, the author extends the theory of the KL-basis to a more general class of Hecke algebras, the so-called algebras with unequal parameters. In particular, he formulates conjectures describing the properties of Hecke algebras with unequal parameters and presents examples verifying these conjectures in particular cases.

Written in the author's precise style, the book gives researchers and graduate students working in the theory of algebraic groups and their representations an invaluable insight and a wealth of new and useful information.

Contents

Coxeter groups
Partial order on W
The algebra {\mathcal H}
The bar operator
The elements c_w
Left or right multiplication by c_s
Dihedral groups
Cells
Cosets of parabolic subgroups
Inversion
The longest element for a finite W
Examples of elements D_w
The function \mathbf{a}
Conjectures
Example: The split case
Example: The quasisplit case
Example: The infinite dihedral case
The ring J
Algebras with trace form
The function {\mathbf{a}}_E
Study of a left cell
Constructible representations
Two-sided cells
Virtual cells
Relative Coxeter groups
Representations
A new realization of Hecke algebras
Bibliography
Other titles in this series

Details:

Series: CRM Monograph Series,Volume: 18
Publication Year: 2003
ISBN: 0-8218-3356-1
Paging: 136 pp.
Binding: Hardcover

Edited by: Yakov Eliashberg, Stanford University, CA, Boris Khesin, University of Toronto, ON, Canada, and Francois Lalonde, University of Quebec at Montreal, Canada

Symplectic and Contact Topology: Interactions and Perspectives

Expected publication date is March 2, 2003

Description
The papers presented in this volume are written by participants of the "Symplectic and Contact Topology, Quantum Cohomology, and Symplectic Field Theory" symposium. The workshop was part of a semester-long joint venture of The Fields Institute in Toronto and the Centre de Recherches Mathematiques in Montreal.

The twelve papers cover the following topics: Symplectic Topology, the interaction between symplectic and other geometric structures, and Differential Geometry and Topology.

The Proceeding concludes with two papers that have a more algebraic character. One is related to the program of Homological Mirror Symmetry: the author defines a category of extended complex manifolds and studies its properties. The subject of the final paper is Non-commutative Symplectic Geometry, in particular the structure of the symplectomorphism group of a non-commutative complex plane.

The in-depth articles make this book a useful reference for graduate students as well as research mathematicians.

Contents

M. Abreu -- Kahler geometry of toric manifolds in symplectic coordinates
V. Apostolov and T. Draghici -- The curvature and the integrability of almost-Kahler manifolds: A survey
F. Bourgeois -- A Morse-Bott approach to contact homology
J. Chen -- Deforming surfaces in four dimensional manifolds
A. Dancer and M. Y. Wang -- Integrability and the Einstein equations
J. Epstein and D. Fuchs -- On the invariants of Legendrian mirror torus links
R. Ibanez, Yu. Rudyak, A. Tralle, and L. Ugarte -- Symplectically harmonic cohomology of nilmanifolds
D. Kotschick -- Godbillon-Vey invariants for families of foliations
S. A. Merkulov -- A note on extended complex manifolds
V. Pidstrygach -- On action of symplectomorphisms of the complex plane on pairs of matrices
L. Polterovich -- Slow symplectic maps, continued fractions, and related stories
J.-C. Sikorav -- The gluing construction for normally generic J-holomorphic curves

Details:

Series: Fields Institute Communications,Volume: 35
Publication Year: 2003
ISBN: 0-8218-3162-3
Paging: approximately 207 pp.
Binding: Hardcover

Philip S. Hirschhorn, Wellesley College, MA

Model Categories and Their Localizations

Description
The aim of this book is to explain modern homotopy theory in a manner accessible to graduate students yet structured so that experts can skip over numerous linear developments to quickly reach the topics of their interest. Homotopy theory arises from choosing a class of maps, called weak equivalences, and then passing to the homotopy category by localizing with respect to the weak equivalences, i.e., by creating a new category in which the weak equivalences are isomorphisms. Quillen defined a model category to be a category together with a class of weak equivalences and additional structure useful for describing the homotopy category in terms of the original category. This allows you to make constructions analogous to those used to study the homotopy theory of topological spaces.

A model category has a class of maps called weak equivalences plus two other classes of maps, called cofibrations and fibrations. Quillen's axioms ensure that the homotopy category exists and that the cofibrations and fibrations have extension and lifting properties similar to those of cofibration and fibration maps of topological spaces. During the past several decades the language of model categories has become standard in many areas of algebraic topology, and it is increasingly being used in other fields where homotopy theoretic ideas are becoming important, including modern algebraic K-theory and algebraic geometry.

All these subjects and more are discussed in the book, beginning with the basic definitions and giving complete arguments in order to make the motivations and proofs accessible to the novice. The book is intended for graduate students and research mathematicians working in homotopy theory and related areas.

Contents
Localization of model category structures
Summary of part 1
Local spaces and localization
The localization model category for spaces
Localization of model categories
Existence of left Bousfield localizations
Existence of right Bousfield localizations
Fiberwise localization
Homotopy theory in model categories
Summary of part 2
Model categories
Fibrant and cofibrant approximations
Simplicial model categories
Ordinals, cardinals, and transfinite composition
Cofibrantly generated model categories
Cellular model categories
Proper model categories
The classifying space of a small category
The Reedy model category structure
Cosimplicial and simplicial resolutions
Homotopy function complexes
Homotopy limits in simplicial model categories
Homotopy limits in general model categories
Index
Bibliography

Details:

eries: Mathematical Surveys and Monographs, Volume: 99
Publication Year: 2003
ISBN: 0-8218-3279-4
Paging: 457 pp.
Binding: Hardcover

Edited by: B. Deschamps, Universite Jean Monnet, St. Etienne, France

Arithmetique des Revetements Algebriques

Expected publication date is March 15, 2003

Description
This book presents articles from the conference on algebraic coverings held in March 2000 in St. Etienne (France). The goal of the conference was to introduce the algebraic bases of this theory and to give a survey of the research tools. These proceedings reflect the spirit of the conference.

The book includes widely accessible survey and research papers on a range of topics, including inverse Galois theory, moduli spaces, problems of descent, rigid geometry, the language of stacks and gerbs and its applications, Galois modules, and morphisms of curves. There is also an appendix with a short lecture on topological and algebraic covers that will make a good introduction to the subject for the non-specialist.

The volume is intended for advanced graduate students and researchers. It would make a nice addition to a seminar on algebraic coverings.


Contents

P. Debes -- Theorie de Galois et geometrie: une introduction
P. Debes -- Methodes topologiques et analytiques en theorie inverse de Galois: Theoreme d'existence de Riemann
Q. Liu -- Une mini introduction a la geometrie analytique rigide
M. Emsalem -- Espaces de Hurwitz
S. Flon -- Corps des modules et bonnes places
J.-C. Douai -- Descente, champs et gerbes de Hurwitz
Ph. Satge -- Morphismes d'une courbe de genre $2$ vers une courbe de genre $1$
N. Borne -- Modules galoisiens sur les courbes: une introduction
P. Debes -- Annexe: Revetements topologiques

Details:

Series: Seminaires et Congres, Number: 5
Publication Year: 2002
ISBN: 2-85629-116-3
Paging: 214 pp.
Binding: Softcover