Olavi Nevanlinna, Helsinki University of Technology, Finland

Meromorphic Functions and Linear Algebra

Description
This volume describes for the first time in monograph form important applications in numerical methods of linear algebra. The author presents new material and extended results from recent papers in a very readable style.

The main goal of the book is to study the behavior of the resolvent of a matrix under the perturbation by low rank matrices. Whereas the eigenvalues (the poles of the resolvent) and the pseudospectra (the sets where the resolvent takes large values) can move dramatically under such perturbations, the growth of the resolvent as a matrix-valued meromorphic function remains essentially unchanged. This has practical implications to the analysis of iterative solvers for large systems of linear algebraic equations.

First, the book introduces the basics of value distribution theory of meromorphic scalar functions. It then introduces a new nonlinear tool for linear algebra, the total logarithmic size of a matrix, which allows for a nontrivial generalization of Rolf Nevanlinna's characteristic function from the scalar theory to matrix- and operator-valued functions. In particular, the theory of perturbations by low rank matrices becomes possible. As an example, if the spectrum of a normal matrix collapses under a low rank perturbation, there is always a compensation in terms of the loss of orthogonality of the eigenvectors. This qualitative phenomenon is made quantitative by using the new tool. Applications are given to rational approximation, to the Kreiss matrix theorem, and to convergence of Krylov solvers.

The book is intended for researchers in mathematics in general and especially for those working in numerical linear algebra. Much of the book is understandable if the reader has a good background in linear algebra and a first course in complex analysis.

Details:

Series: Fields Institute Monographs, Volume: 18
Publication Year: 2003
ISBN: 0-8218-3247-6
Paging: 136 pp.
Binding: Hardcover

Edited by: Seok-Jin Kang, Korea Institute for Advanced Study, Seoul, Korea, and Kyu-Hwan Lee, University of Toronto, ON, Canada

Combinatorial and Geometric Representation Theory

Expected publication date is April 27, 2003

Description
This volume presents the proceedings of the international conference on Combinatorial and Geometric Representation Theory. In the field of representation theory, a wide variety of mathematical ideas are providing new insights, giving powerful methods for understanding the theory, and presenting various applications to other branches of mathematics. Over the past two decades, there have been remarkable developments. This book explains the strong connections between combinatorics, geometry, and representation theory. It is suitable for graduate students and researchers interested in representation theory.

Contents

H. H. Andersen -- Twisted Verma modules and their quantized analogues
S. Ariki -- On tameness of the Hecke algebras of type B
G. Benkart and D. Moon -- Tensor product representations of Temperley-Lieb algebras and their centralizer algebras
J. F. Carlson, Z. Lin, D. K. Nakano, and B. J. Parshall -- The restricted nullcone
W. J. Haboush -- Projective embeddings of varieties of special lattices
G. James -- Representations of general linear groups
S.-J. Kang and J.-H. Kwon -- Fock space representations for the quantum affine algebra U_q(C_2^{(1)})
M. Kashiwara -- Realizations of crystals
H. Nakajima -- t-analogs of q-characters of quantum affine algebras of type A_n, D_n
A. Ram -- Skew shape representations are irreducible

Details:

Series: Contemporary Mathematics, Volume: 325
Publication Year: 2003
ISBN: 0-8218-3212-3
Paging: 189 pp.
Binding: Softcover

Edited by: M. Chidami, University of Rabat, Morocco, R. Curto, University of Iowa, Iowa City, IA, M. Mbekhta, University of Lille, France, F.-H. Vasilescu, University of Lille I, France, and J. Zemanek, Institute of Mathematics, Warsaw, Poland

Operator Theory and Banach Algebras

A publication of the Theta Foundation.
Expected publication date is May 30, 2003

Description
This volume contains the proceedings of the International Conference on Operator Theory and Banach Algebras. Over 70 participants from the world over attended. The book contains 14 selected refereed papers; three are written in English and the rest in French. Half are survey papers referring to different domains; the remaining papers contain original results with complete proofs.

The main topics covered are the spectral theory of operators on a Banach space, classes of topological algebras with applications to physics, different classes of operators on Hilbert and Banach space, problems in Banach algebras, Lie algebras of operators, interaction between complex analysis and operator theory, and semigroups of operators.

All papers have been revised to account for recent developments. Overall, they present an accurate overview of the domains considered.

Contents

P. Aiena and M. Gonzalez -- Improjective operators which are not inessential
M. Akkar, R. A. Hassani, and A. Blali -- C-semi-groupes (alpha-integres affilies a des algebres d'operateurs
B. Aupetit, E. Makai, M. Mbekhta, and J. Zemanek -- The connected components of the idempotents in the Calkin algebra and their liftings
F. Bagarello -- Quantum models and locally convex ast-algebras
M. Cabrera and A. A. Mohammed -- Algebra of quotients with bounded evaluation of a normed prime algebra
G. Cassier -- Autour de quelques interactions recentes entre l'analyse complexe et la theorie des operateurs
R. E. Curto and W. Y. Lee -- Subnormality and k-hyponormality
K. B. Laursen -- (delta)ecomposa(beta)ility
L. W. Marcoux -- A survey of (U+K)-orbits
A. Micali -- Sur les algebres de Banach-Bernstein
M. M. Neumann -- Intertwining restrictions and quotients of decomposable operators
A. R. Sourour -- The Lie structure of certain algebras of operators
C. Trapani -- CQ^ast-algebras of operators: density properties
F.-H. Vasilescu -- Extensions of unbounded symmetric multioperators

Details:

Publisher: Theta Foundation
Publication Year: 2003
ISBN: 973-85432-1-5
Paging: 166 pp.
Binding: Softcover


Xavier Buff, Universite Paul Sabatier, Toulouse, France, Jerome Fehrenbach, University of Nice Sophia-Antipolis, Valbonne, France, Pierre Lochak, Centre de Mathematiques de Jussieu, Universite Paris VI, Paris, France, Leila Schneps, Universite Paris VI, France, and Pierre Vogel, Universite Paris VII, France

Moduli Spaces of Curves, Mapping Class Groups and Field Theory

Expected publication date is July 5, 2003

From a review of the French edition:

"A collective monograph dedicated to the new and profound relations between various theories previously considered as unrelated ... A specific feature of the book, which distinguishes it from many other monographs and textbooks on the same subjects, is its nature of a `guide for the non-specialist' ... it also contains full proofs of some results difficult to find elsewhere ... Examples are studied in great detail ... Recommended as a first reading for a non-specialist who wants to get acquainted with the subject but who does not want to get lost in its many intricacies and ramifications."

-- Mathematical Reviews

Description
This is a collection of articles that grew out of a workshop organized to discuss deep links among various topics that were previously considered unrelated. Rather than a typical workshop, this gathering was unique as it was structured more like a course for advanced graduate students and research mathematicians.

In the book, the authors present applications of moduli spaces of Riemann surfaces in theoretical physics and number theory and on Grothendieck's dessins d'enfants and their generalizations. Chapter 1 gives an introduction to Teichmuller space that is more concise than the popular textbooks, yet contains full proofs of many useful results which are often difficult to find in the literature. This chapter also contains an introduction to moduli spaces of curves, with a detailed description of the genus zero case, and in particular of the part at infinity. Chapter 2 takes up the subject of the genus zero moduli spaces and gives a complete description of their fundamental groupoids, based at tangential base points neighboring the part at infinity; the description relies on an identification of the structure of these groupoids with that of certain canonical subgroupoids of a free braided tensor category. It concludes with a study of the canonical Galois action on the fundamental groupoids, computed using Grothendieck-Teichmuller theory. Finally, Chapter 3 studies strict ribbon categories, which are closely related to braided tensor categories: Here they are used to construct invariants of 3-manifolds which in turn give rise to quantum field theories. The material is suitable for advanced graduate students and researchers interested in algebra, algebraic geometry, number theory, and geometry and topology.

Contents

X. Buff, J. Fehrenbach, and P. Lochak -- Elements of the geometry of moduli spaces of curves
L. Schneps -- Fundamental groupoids of genus zero moduli spaces and braided tensor categories
P. Vogel -- Witten-Reshetikhin-Turaev invariants and quantum field theories

Details:

Publisher: American Mathematical Society
Distributor: American Mathematical Society
Series: SMF/AMS Texts and Monographs, Volume: 9
Publication Year: 2003
ISBN: 0-8218-3167-4
Paging: 131 pp.
Binding: Softcover

L. Lafforgue, Institut des Hautes Etudes Scientifiques, Bures-sur-Yvette, France

Chirurgie des grassmanniennes

Expected publication date is June 7, 2003

Description
The AMS now makes available this succinct and quite elegant research monograph written by Fields Medalist and eminent researcher, Laurent Lafforgue. The material is an outgrowth of Lafforgue's lectures and seminar at the Centre de Recherches Mathematiques (University of Montreal, PQ, Canada) where he held the 2001-2002 Aisenstadt Chair.

In the book, he addresses an important recurrent theme of modern mathematics: the various compactifications of moduli spaces, which have a large number of applications. This book treats the case of thin Schubert varieties, which are natural subvarieties of Grassmannians. He was led to these questions by a particular case linked to his work on the Langlands program. In this monograph, he develops the theory in a more systematic way, which exhibits strong similarities with the case of moduli of stable curves.

Prerequisites are minimal and include basic algebraic geometry, and standard facts about Grassmann varieties, their Plucker embeddings, and toric varieties. The book is suitable for advanced graduate students and research mathematicians interested in the classification of moduli spaces.

Contents

Cellules de Schubert minces et espaces de configurations de matroides
Compactifications: Pavages de convexes entiers et recollement des cellules de Schubert minces
Etude de quelques familles simples de compactifications
Le fibre equivariant universel sur la variete torique des facettes des pavages
Variations de varietes projectives rationneles avec structures logarithmiques
References bibliographiques

Details:

Series: CRM Monograph Series, Volume: 19
Publication Year: 2003
ISBN: 0-8218-3358-8
Paging: 170 pp.
Binding: Hardcover