Introduction In the last few years a few monographs dedicated to the theory of topolog ical rings have appeared [Warn27], [Warn26], [Wies 19], [Wies 20], [ArnGM]. Ring theory can be viewed as a particular case of Z-algebras. Many general results true for rings can be extended to algebras over commutative rings. In topological algebra the structure theory for two classes of topological algebras is well developed: Banach algebras; and locally compact rings. The theory of Banach algebras uses results of Banach spaces, and the theory of locally compact rings uses the theory of LCA groups. As far as the author knows, the first papers on the theory of locally compact rings were [Pontr1]' [J1], [J2], [JT], [An], lOt], [K1]' [K2]' [K3], [K4], [K5], [K6]. Later two papers, [GS1,GS2]appeared, which contain many results concerning locally compact rings. This book can be used in two w.ays. It contains all necessary elementary results from the theory of topological groups and rings. In order to read these parts of the book the reader needs to know only elementary facts from the theories of groups, rings, modules, topology. The book consists of two parts.

The aim of this book is to extend the understanding of the fundamental role of generalizations of Lie and related non-commutative and non-associative structures in Mathematics and Physics. This is a thematic volume devoted to the interplay between several rapidly exp- ding research ?elds in contemporary Mathematics and Physics, such as generali- tions of the main structures of Lie theory aimed at quantization and discrete and non-commutative extensions of differential calculus and geometry, non-associative structures, actions of groups and semi-groups, non-commutative dynamics, n- commutative geometry and applications in Physics and beyond. The speci?c ?elds covered by this volume include: * Applications of Lie, non-associative and non-commutative associative structures to generalizations of classical and quantum mechanics and non-linear integrable systems, operadic and group theoretical methods; * Generalizations and quasi-deformations of Lie algebras such as color and super Lie algebras, quasi-Lie algebras, Hom-Lie algebras, in?nite-dimensional Lie algebras of vector ?elds associated to Riemann surfaces, quasi-Lie algebras of Witt type and their central extensions and deformations important for in- grable systems, for conformal ? eld theory and for string theory; * Non-commutative deformation theory, moduli spaces and interplay with n- commutativegeometry,algebraicgeometryandcommutativealgebra,q-deformed differential calculi and extensions of homological methods and structures; * Crossed product algebras and actions of groups and semi-groups, graded rings and algebras, quantum algebras, twisted generalizations of coalgebras and Hopf algebra structures such as Hom-coalgebras, Hom-Hopf algebras, and super Hopf algebras and their applications to bosonisation, parastatistics, parabosonic and parafermionic algebras, orthoalgebas and root systems in quantum mechanics;

This book is intended to provide a reasonably self-contained account of a major portion of the general theory of rings and modules suitable as a text for introductory and more advanced graduate courses. We assume the famil iarity with rings usually acquired in standard undergraduate algebra courses. Our general approach is categorical rather than arithmetical. The continuing theme of the text is the study of the relationship between the one-sided ideal structure that a ring may possess and the behavior of its categories of modules. Following a brief outline of set-theoretic and categorical foundations, the text begins with the basic definitions and properties of rings, modules and homomorphisms and ranges through comprehensive treatments of direct sums, finiteness conditions, the Wedderburn-Artin Theorem, the Jacobson radical, the hom and tensor functions, Morita equivalence and duality, de composition theory of injective and projective modules, and semi perfect and perfect rings. In this second edition we have included a chapter containing many of the classical results on artinian rings that have hdped to form the foundation for much of the contemporary research on the representation theory of artinian rings and finite dimensional algebras. Both to illustrate the text and to extend it we have included a substantial number of exercises covering a wide spectrum of difficulty. There are, of course" many important areas of ring and module theory that the text does not touch upon."

This book is concerned with discontinuous groups of motions of the unique connected and simply connected Riemannian 3-manifold of constant curva ture -1, which is traditionally called hyperbolic 3-space. This space is the 3-dimensional instance of an analogous Riemannian manifold which exists uniquely in every dimension n:::: 2. The hyperbolic spaces appeared first in the work of Lobachevski in the first half of the 19th century. Very early in the last century the group of isometries of these spaces was studied by Steiner, when he looked at the group generated by the inversions in spheres. The ge ometries underlying the hyperbolic spaces were of fundamental importance since Lobachevski, Bolyai and Gauss had observed that they do not satisfy the axiom of parallels. Already in the classical works several concrete coordinate models of hy perbolic 3-space have appeared. They make explicit computations possible and also give identifications of the full group of motions or isometries with well-known matrix groups. One such model, due to H. Poincare, is the upper 3 half-space IH in JR . The group of isometries is then identified with an exten sion of index 2 of the group PSL(2,"

Algebraic K-Theory plays an important role in many areas of modern mathematics: most notably algebraic topology, number theory, and algebraic geometry, but even including operator theory. The broad range of these topics has tended to give the subject an aura of inapproachability. This book, based on a course at the University of Maryland in the fall of 1990, is intended to enable graduate students or mathematicians working in other areas not only to learn the basics of algebraic K-Theory, but also to get a feel for its many applications. The required prerequisites are only the standard one-year graduate algebra course and the standard introductory graduate course on algebraic and geometric topology. Many topics from algebraic topology, homological algebra, and algebraic number theory are developed as needed. The final chapter gives a concise introduction to cyclic homology and its interrelationship with K-Theory.

This book is the first monograph on the theory of endomorphism rings of Abelian groups. The theory is a rapidly developing area of algebra and has its origin in the theory of operators of vector spaves. The text contains additional information on groups themselves, introducing new concepts, methods, and classes of groups. All the main fields of the theory of endomorphism rings of Abelian groups from early results to the most recent are covered. Neighbouring results on endomorphism rings of modules are also mentioned.
This text has many pedagogical features:

-all the necessary definitions and formulations of assertions on Abelian groups, rings, and modules are gathered in the first two sections;
-each chapter begins with a brief summary of results;
-there are exercises of varying difficulty in each section;
-lesser known facts on rings and modules are presented with proofs;
-there are comments at the end of each chapter together with a brief historical review as well as a look at the future direction of modern research;
-an extensive bibliography is provided. This book will be invaluable as a background text for introductory as well as advanced graduate courses. Professional algebraists might find it useful as a first systematic presentation of results previously only to be found scattered throughout various journals.

Offering the most geometric presentation available, Linear Algebra with Applications, Fifth Edition emphasizes linear transformations as a unifying theme. This elegant textbook combines a user-friendly presentation with straightforward, lucid language to clarify and organize the techniques and applications of linear algebra. Exercises and examples make up the heart of the text, with abstract exposition kept to a minimum. Exercise sets are broad and varied and reflect the author's creativity and passion for this course. This revision reflects careful review and appropriate edits throughout, while preserving the order of topics of the previous edition.

Structured matrices serve as a natural bridge between the areas of algebraic computations with polynomials and numerical matrix computations, allowing cross-fertilization of both fields. This book covers most fundamental numerical and algebraic computations with Toeplitz, Hankel, Vandermonde, Cauchy, and other popular structured matrices. Throughout the computations, the matrices are represented by their compressed images, called displacements, enabling both a unified treatment of various matrix structures and dramatic saving of computer time and memory. The resulting superfast algorithms allow further dramatic parallel acceleration using FFT and fast sine and cosine transforms. Included are specific applications to other fields, in particular, superfast solutions to: various fundamental problems of computer algebra; the tangential Nevanlinna--Pick and matrix Nehari problems The primary intended readership for this work includes researchers, algorithm designers, and advanced graduate students in the fields of computations with structured matrices, computer algebra, and numerical rational interpolation. The book goes beyond research frontiers and, apart from very recent research articles, includes yet unpublished results. To serve a wider audience, the presentation unfolds systematically and is written in a user-friendly engaging style. Only some preliminary knowledge of the fundamentals of linear algebra is required. This makes the material accessible to graduate students and new researchers who wish to study the rapidly exploding area of computations with structured matrices and polynomials. Examples, tables, figures, exercises, extensive bibliography, and index lend this text toclassroom use or self-study.

1 Grundlagen.- 1.1 Allgemeine Grundlagen.- 1.1.1 Ziele und Aufgaben.- 1.1.2 Methoden.- 1.1.3 Geschichte und Einordnung.- 1.1.3.1 Geschichte der Bauwerksvermessung.- 1.1.3.2 Geschichte des Vermessungswesens.- 1.1.3.3 Geschichte der Architekturphotogrammetrie.- 1.1.4 Rechtliche Grundlagen und Rahmenbedingungen.- 1.1.4.1 Internationale Vereinbarungen und Organisationen.- 1.1.4.2 Baugesetzbuch, Denkmalpflegegesetze, Vermessungsgesetze.- 1.2 Messgroessen und Masseinheiten.- 1.2.1 Strecken.- 1.2.2 Winkel.- 1.3 Bezugssysteme und Koordinaten.- 1.3.1 Bezugsflachen.- 1.3.2 Koordinaten.- 1.3.3 Koordinatensysteme.- 1.3.3.1 Polarkoordinaten.- 1.3.3.2 Lokale Koordinatensysteme.- 1.3.3.3 Regionale Koordinatensysteme.- 1.3.3.4 Globale Koordinatensysteme.- 1.3.3.5 Geographische Koordinaten.- 1.3.3.6 Geozentrische Koordinaten.- 1.3.4 Koordinatentransformationen.- 1.3.4.1 Translation (2D).- 1.3.4.2 Massstabslose Transformation (2D).- 1.3.4.3 AEhnlichkeitstransformation (2D).- 1.3.4.4 Vereinfachte AEhnlichkeitstransformation mit 2 Passpunkten (2D).- 1.3.4.5 Affintransformation (2D).- 1.3.4.6 Weitere ebene Koordinatentransformationen.- 1.3.4.7 Raumliche Koordinatentransformation (3D).- 1.3.5 Festpunktfelder.- 1.3.5.1 Netz trigonometrischer Punkte zur Lagedefinition.- 1.3.5.2 Hoehennetz.- 1.3.6 Vermessungsnetze fur die Bauwerksvermessung.- 1.3.6.1 Netzdesign.- 1.3.6.2 Vermarkung.- 1.3.6.3 Design und Fertigung von Punktsignalisierungen.- 1.3.6.4 Auswahl naturlicher Passpunkte.- 1.3.6.5 Schnurnetz zur temporaren Vermarkung.- 1.3.6.6 Punktubersichten und Einmessskizzen.- 1.4 Fehlerlehre und Statistik.- 1.4.1 Fehlerarten und ihre Wirkung.- 1.4.1.1 Zufallige Fehler.- 1.4.1.2 Systematische Fehler.- 1.4.1.3 Grobe Fehler.- 1.4.2 Fehlerfortpflanzung und Ausgleichsrechnung.- 1.4.3 Rechenscharfe und Rundung.- 1.4.4 Toleranzen im Bauwesen.- 2 Dokumentation von Gebauden und Ensembles.- 2.1 Amtliche Dokumentation.- 2.1.1 Katasterunterlagen.- 2.1.2 Amtliche Karten.- 2.1.3 Lageplan.- 2.1.4 Geoinformationssysteme (GIS).- 2.2 Plane.- 2.2.1 Grundriss.- 2.2.2 Schnitt.- 2.2.3 Ansicht.- 2.2.4 Detaildarstellungen.- 2.2.5 Massstabe und Detaillierungsgrad.- 2.2.6 Materialien und Aufbewahrung.- 2.3 3D-Beschreibungen.- 2.3.1 CAD-Modell.- 2.3.2 Animation.- 2.3.3 Virtual Reality.- 2.3.4 Augmented Reality.- 2.4 Fotografie.- 2.4.1 Analoge Fotografie.- 2.4.1.1 Fotografisches Material.- 2.4.1.2 Kameras.- 2.4.1.3 Objektive.- 2.4.1.4 Licht.- 2.4.1.5 Belichtung.- 2.4.1.6 Archivierungen von Fotomaterialien.- 2.4.2 Digitale Bilder.- 2.4.2.1 Flachensensoren.- 2.4.2.2 Zeilenkameras.- 2.4.2.3 Spezialkameras.- 2.4.3 Scannen analoger Fotovorlagen.- 2.4.4 Digitale Bildverarbeitung.- 2.5 Textliche und hybride Beschreibungen.- 2.5.1 Raumbuch.- 2.5.2 Hypertext Dokumente.- 2.5.3 Informationssystem.- 2.6 Archivierung digitaler Daten.- 2.6.1 Datentrager.- 2.6.2 Datenformate.- 2.6.2.1 Texte.- 2.6.2.2 Datenbanken.- 2.6.2.3 Vektordaten.- 2.6.2.4 Rasterdaten.- 2.6.2.5 Hypermedia.- 3 Erfassung von Messelementen.- 3.1 Messprinzipien.- 3.1.1 Vom-Grossen-ins-Kleine.- 3.1.2 UEberbestimmungen.- 3.1.3 Vermeidung von systematischen Fehlern.- 3.2 Gerate und Instrumente.- 3.2.1 Bauteile, Kleingerate und Zubehoer.- 3.2.1.1 Lote und Libellen.- 3.2.1.2 Fernrohr.- 3.2.1.3 Stative.- 3.2.1.4 Fluchtstab.- 3.2.1.5 Nivellierlatten und Kleingerat.- 3.2.1.6 Aufstellen eines Instruments.- 3.2.2 Winkelmessung.- 3.2.2.1 Bestimmung rechter Winkel.- 3.2.2.2 Theodolit.- 3.2.2.3 Satzmessung.- 3.2.2.4 Berechnung von Richtungswinkeln aus Koordinaten.- 3.2.3 Streckenmessung.- 3.2.3.1 Streckenmessung mit dem Messband.- 3.2.3.2 Optische Streckenmessung.- 3.2.3.3 Elektro-optische Entfernungsmessung (EDM).- 3.2.4 Hoehenmessung.- 3.2.4.1 Einfache Werkzeuge.- 3.2.4.2 Nivellement.- 3.2.4.3 Rotationslaser.- 3.3 Beschaffung einer Vermessungsausrustung.- 4 Messverfahren.- 4.1 Schrittskizze.- 4.2 Handaufmass.- 4.3 Punktbestimmung ohne Theodolit.- 4.3.1 Bogenschlag.- 4.3.2 Einbindeverfahren.- 4.3.3 Orthogonalverfahren.- 4.3.4

The aim of this book is to present a substantial part of matrix analysis that is functional analytic in spirit. Much of this will be of interest to graduate students and research workers in operator theory, operator algebras, mathematical physics and numerical analysis. The book can be used as a basic text for graduate courses on advanced linear algebra and matrix analysis. It can also be used as supplementary text for courses in operator theory and numerical analysis. Among topics covered are the theory of majorization, variational principles for eigenvalues, operator monotone and convex functions, perturbation of matrix functions and matrix inequalities. Much of this is presented for the first time in a unified way in a textbook. The reader will learn several powerful methods and techniques of wide applicability, and see connections with other areas of mathematics. A large selection of matrix inequalities will make this book a valuable reference for students and researchers who are working in numerical analysis, mathematical physics and operator theory.

Metagraphs and Their Applications is a presentation of metagraph theory and its applications that begins by defining a metagraph and its uses. They are more complex than a simple graph structure, but they allow for representation and analysis of more complex systems. The material contained in this book is presented in two parts. The first develops the theoretical results with the emphasis on the development of a metagraph algebra. In the second part of the book, four promising applications of metagraphs are examined: modeling of data relations; the modeling of decision models; the modeling of decision rules; and the modeling of workflow tasks. Hence, the theoretical results in the initial chapters lay the foundation for the application areas in the second part of the book. The book concludes by examining several possible extensions of this work.

A look at solving problems in three areas of classical elementary mathematics: equations and systems of equations of various kinds, algebraic inequalities, and elementary number theory, in particular divisibility and diophantine equations. In each topic, brief theoretical discussions are followed by carefully worked out examples of increasing difficulty, and by exercises which range from routine to rather more challenging problems. While it emphasizes some methods that are not usually covered in beginning university courses, the book nevertheless teaches techniques and skills which are useful beyond the specific topics covered here. With approximately 330 examples and 760 exercises.

The theme of this book is operator theory on C*-algebras. The main novel tool employed is the concept of local multipliers. Originally devised by Elliott and Pedersen in the 1970's in order to study derivations and automorphisms, local multipliers of C*-algebras were developed into a powerful device by the present authors in the 1990's. The book serves two purposes. The first part provides the reader - specialist and advanced graduate student alike - with a thorough introduction to the theory of local multipliers. Only a minimal knowledge of algebra and analysis is required, as the prerequisites in both non-commutative ring theory and basic C*-algebra theory are presented in the first chapter. In the second part, local multipliers are used to obtain a wealth of information on various classes of operators on C*-algebras, including (groups of) automorphisms, derivations, elementary operators, Lie isomorphisms and Lie derivations, as well as others. Many of the results appear in print for the first time. The authors have made an effort to avoid intricate technicalities thus some of the results are not pushed to their utmost generality. Several open problems are discussed, and hints for further developments are given.

The mathematical theory of wavelets is less than 15 years old, yet already wavelets have become a fundamental tool in many areas of applied mathematics and engineering. This introduction to wavelets assumes a basic background in linear algebra (reviewed in Chapter 1) and real analysis at the undergraduate level. Fourier and wavelet analyses are first presented in the finite-dimensional context, using only linear algebra. Then Fourier series are introduced in order to develop wavelets in the infinite-dimensional, but discrete context. Finally, the text discusses Fourier transform and wavelet theory on the real line. The computation of the wavelet transform via filter banks is emphasized, and applications to signal compression and numerical differential equations are given. This text is ideal for a topics course for mathematics majors, because it exhibits and emerging mathematical theory with many applications. It also allows engineering students without graduate mathematics prerequisites to gain a practical knowledge of wavelets.

Vertex algebra was introduced by Boreherds, and the slightly revised notion "vertex oper- ator algebra" was formulated by Frenkel, Lepowsky and Meurman, in order to solve the problem of the moonshine representation of the Monster group - the largest sporadie group. On the one hand, vertex operator algebras ean be viewed as extensions of eertain infinite-dimensional Lie algebras such as affine Lie algebras and the Virasoro algebra. On the other hand, they are natural one-variable generalizations of commutative associative algebras with an identity element. In a certain sense, Lie algebras and commutative asso- ciative algebras are reconciled in vertex operator algebras. Moreover, some other algebraie structures, such as integral linear lattiees, Jordan algebras and noncommutative associa- tive algebras, also appear as subalgebraic structures of vertex operator algebras. The axioms of vertex operator algebra have geometrie interpretations in terms of Riemman spheres with punctures. The trace functions of a certain component of vertex operators enjoy the modular invariant properties. Vertex operator algebras appeared in physies as the fundamental algebraic structures of eonformal field theory, whieh plays an important role in string theory and statistieal meehanies. Moreover,eonformalfieldtheoryreveals animportantmathematiealproperty,the so called "mirror symmetry" among Calabi-Yau manifolds. The general correspondence between vertex operator algebras and Calabi-Yau manifolds still remains mysterious. Ever since the first book on vertex operator algebras by Frenkel, Lepowsky and Meur- man was published in 1988, there has been a rapid development in vertex operator su- peralgebras, which are slight generalizations of vertex operator algebras.

The topic of this book is finite group actions and their use in order to approach finite unlabeled structures by defining them as orbits of finite groups of sets. Well-known examples are graph, linear codes, chemical isomers, spin configurations, isomorphism classes of combinatorial designs etc.The second edition is an extended version and puts more emphasis on applications to the constructive theory of finite structures. Recent progress in this field, in particular in design and coding theory, is described.This book will be of great use to researchers and graduate students.

This book presents the state-of-the-art research on the teaching and learning of linear algebra in the first year of university, in an international perspective. It provides university teachers in charge of linear algebra courses with a wide range of information from works including theoretical and experimental issues.

This book presents tensors and tensor analysis as primary mathematical tools for engineering and engineering science students and researchers. The discussion is based on the concepts of vectors and vector analysis in three-dimensional Euclidean space, and although it takes the subject matter to an advanced level, the book starts with elementary geometrical vector algebra so that it is suitable as a first introduction to tensors and tensor analysis. Each chapter includes a number of problems for readers to solve, and solutions are provided in an Appendix at the end of the text. Chapter 1 introduces the necessary mathematical foundations for the chapters that follow, while Chapter 2 presents the equations of motions for bodies of continuous material. Chapter 3 offers a general definition of tensors and tensor fields in three-dimensional Euclidean space. Chapter 4 discusses a new family of tensors related to the deformation of continuous material. Chapter 5 then addresses constitutive equations for elastic materials and viscous fluids, which are presented as tensor equations relating the tensor concept of stress to the tensors describing deformation, rate of deformation and rotation. Chapter 6 investigates general coordinate systems in three-dimensional Euclidean space and Chapter 7 shows how the tensor equations discussed in chapters 4 and 5 are presented in general coordinates. Chapter 8 describes surface geometry in three-dimensional Euclidean space, Chapter 9 includes the most common integral theorems in two- and three-dimensional Euclidean space applied in continuum mechanics and mathematical physics.

Symmetry and Economic Invariance: An Introduction explores how symmetry and invariance of economic models can provide insights into their properties. While the professional economist is nowadays adept at many of the mathematical techniques used in static and dynamic optimization models, group theory is still not among his or her repertoire of tools. The authors aim to show that group theoretic methods form a natural extension of the techniques commonly used in economics and that they can be easily mastered.

to Group Rings by Cesar Polcino Milies Instituto de Matematica e Estatistica, Universidade de sao Paulo, sao Paulo, Brasil and Sudarshan K. Sehgal Department of Mathematical and Statistical Sciences, University of Alberta, Edmonton. Canada SPRINGER-SCIENCE+BUSINESS MEDIA, B.V. A c.I.P. Catalogue record for this book is available from the Library of Congress. ISBN 978-1-4020-0239-7 ISBN 978-94-010-0405-3 (eBook) DOI 10.1007/978-94-010-0405-3 Printed an acid-free paper AII Rights Reserved (c) 2002 Springer Science+Business Media Dordrecht Originally published by Kluwer Academic Publishers in 2002 Softcover reprint ofthe hardcover Ist edition 2002 No part of the material protected by this copyright notice may be reproduced or utilized in any form or by any means, electronic or mechanical, inc1uding photocopying, recording Of by any information storage and retrieval system, without written permis sion from the copyright owner. Contents Preface ix 1 Groups 1 1.1 Basic Concepts . . . . . . . . . . . . 1 1.2 Homomorphisms and Factor Groups 10 1.3 Abelian Groups . 18 1.4 Group Actions, p-groups and Sylow Subgroups 21 1.5 Solvable and Nilpotent Groups 27 1.6 FC Groups .

Accurate and efficient computer algorithms for factoring matrices, solving linear systems of equations, and extracting eigenvalues and eigenvectors. Regardless of the software system used, the book describes and gives examples of the use of modern computer software for numerical linear algebra. It begins with a discussion of the basics of numerical computations, and then describes the relevant properties of matrix inverses, factorisations, matrix and vector norms, and other topics in linear algebra. The book is essentially self- contained, with the topics addressed constituting the essential material for an introductory course in statistical computing. Numerous exercises allow the text to be used for a first course in statistical computing or as supplementary text for various courses that emphasise computations.

ClDo _ IIIIIIIoaIIIics bu _ die 'EI JDDi, sij'_ . . . . -. . . _. je _ . . . . . lIbupalaJllllllllll __ D'y_poa: wbae it beIoap. . . . die . . ." . ., . . _ DOD to dlecluly __ __ . 1110 _ is dioapaI; -. . e _ may be EricT. BeD IbIetodo--'_iL O. 1feaoriIide Mathematics is a tool for dloogIrt. A bighly necessary tool in a world where both feedback and noolineari ties abound. Similarly, all kinds of parts of IIIIIIhcmatiI: s serve as tools for odIcr parts and for ocher sci eoccs. Applying a simple rewriting rule to the quote on the right above one finds suc: h stalements as: 'One ser vice topology has rcncIerM mathematical physics . . . '; 'One service logic has rendered computer science . . '; 'One service category theory has rmdcn: d mathematics . . . '. All arguably true. And all statements obrainable this way form part of the raison d'etm of this series. This series, Mathmlatics tDIII Its Applications, saaned in 1977. Now that over one hundred volumcs have appeared it seems opportune to reexamine its scope. AI. the time I wrote "Growing spccialization and divenification have brought a host of monographs and textbooks on incJeasingly specialized topics. However, the 'tree' of knowledge of JJJatbcmatics and reIatcd ficIds docs not grow only by putting forth new bnDdIcs. It also happens, quite often in fact, that brancbes which were thought to be comp1etcly disparate am suddenly seen to be rdatcd."

A description of 148 algorithms fundamental to number-theoretic computations, in particular for computations related to algebraic number theory, elliptic curves, primality testing and factoring. The first seven chapters guide readers to the heart of current research in computational algebraic number theory, including recent algorithms for computing class groups and units, as well as elliptic curve computations, while the last three chapters survey factoring and primality testing methods, including a detailed description of the number field sieve algorithm. The whole is rounded off with a description of available computer packages and some useful tables, backed by numerous exercises. Written by an authority in the field, and one with great practical and teaching experience, this is certain to become the standard and indispensable reference on the subject.

The theory of operators stands at the intersection of the frontiers of modern analysis and its classical counterparts; of algebra and quantum mechanics; of spectral theory and partial differential equations; of the modern global approach to topology and geometry; of representation theory and harmonic analysis; and of dynamical systems and mathematical physics. The present collection of papers represents contributions to a conference, and they have been carefully selected with a view to bridging different but related areas of mathematics which have only recently displayed an unexpected network of interconnections, as well as new and exciting cross-fertilizations. Our unify ing theme is the algebraic view and approach to the study of operators and their applications. The complementarity between the diversity of topics on the one hand and the unity of ideas on the other has been stressed. Some of the longer contributions represent material from lectures (in expanded form and with proofs for the most part). However, the shorter papers, as well as the longer ones, are an integral part of the picture; they have all been carefully refereed and revised with a view to a unity of purpose, timeliness, readability, and broad appeal. Raul Curto and Paile E. T."