by N.R. Bruin

Chabauty methods and covering techniques applied to generalized Fermat equations

CWI Tract 133
Summary
This text, derived from the thesis of the author, is concerned with solving equations of the form $$x^r+y^s=z^t$$ in coprime integers $x,y,z$ for fixed $r,s,t$. For specific values of $r,s,t$, this question is reduced to finding the rational points on finitely many algebraic curves.
These curves have a map to the projective line that factors through an elliptic curve, but only over an extension of the base field. This leads to the question of determining the rational points on an elliptic curve over a number field, subject to additional arithmetic restrictions. An adaptation of a method first used by Chabauty enables the resolution of this problem. In the text, the coprime integer solutions to the equations $x^2+y^3=z^8$, $x^2+y^8=z^3$, $x^2+y^4=z^5$ and $x^2+y^5=z^4$ are determined.
The methods developed are applicable to hyperelliptic curves in general, as well as to some other classes of curves.

2002, ISBN 90 6196 508 X, 77 pages,

Edited by: Laurent Bonavero and Michel Brion, Institut Fourier, Saint-Martin d'Heres, France

Geometry of Toric Varieties

A publication of the Societe Mathematique de France.

Description

Toric varieties form a beautiful class of algebraic varieties, which are often used as a testing ground for verifying general conjectures in algebraic geometry, for example, in Hilbert schemes, singularity theory, Mori theory, and so on.

This volume gathers expanded versions of lectures presented during the summer school of "Geometry of Toric Varieties" in Grenoble (France). These lectures were given during the second and third weeks of the school. (The first week was devoted to introductory material.) The paper by D. Cox is an overview of recent work in toric varieties and its applications, putting the other contributions of the volume into perspective.

Contents

D. A. Cox -- Update on toric geometry
W. Bruns and J. Gubeladze -- Semigroup algebras and discrete geometry
A. Craw and M. Reid -- How to calculate A-Hilb $\mathbb{C}^3$
D. I. Dais -- Resolving 3-dimensional toric singularities
D. I. Dais -- Crepant resolutions of Gorenstein toric singularities and upper bound theorem
J. Hausen -- Producing good quotients by embedding into toric varieties
Y. Ito -- Special McKay correspondence
Y. Tschinkel -- Lectures on height zeta functions of toric varieties
J. A. Wisniewski -- Toric Mori theory and Fano manifolds

Details:

Series: Seminaires et Congres, Number: 6
Publication Year: 2002
ISBN: 2-85629-122-8
Paging: 272 pp.
Binding: Softcover

Peter Pesic

Abel's Proof
An Essay on the Sources and Meaning of Mathematical Unsolvability

ISBN 0-262-16216-4
5 3/8 x 8, 216 pp., 46 illus.(CLOTH)

In 1824 a young Norwegian named Niels Henrik Abel proved conclusively that algebraic equations of the fifth order are not solvable in radicals. In this book Peter Pesic shows what an important event this was in the history of thought. He also presents it as a remarkable human story. Abel was twenty-one when he self-published his proof, and he died five years later, poor and depressed, just before it started to receive wide acclaim. Abel's attempts to reach out to the mathematical elite of the day had been spurned, and he was unable to find a position that would allow him to work in peace and marry his fiancee.

But Pesic's story begins long before Abel and continues to the present day, for Abel's proof changed how we think about mathematics and its relation to the "real" world. Starting with the Greeks, who invented the idea of mathematical proof, Pesic shows how mathematics found its sources in the real world (the shapes of things, the accounting needs of merchants) and then reached beyond those sources toward something more universal. The Pythagoreans' attempts to deal with irrational numbers foreshadowed the slow emergence of abstract mathematics. Pesic focuses on the contested development of algebra--which even Newton resisted--and the gradual acceptance of the usefulness and perhaps even beauty of abstractions that seemed to invoke realities with dimensions outside of human experience. Pesic tells this story as a history of ideas, with mathematical details incorporated in boxes. The book also includes a new annotated translation of Abel's original proof.

Jeremy J. Gray

Janos Bolyai, Euclid, and the Nature of Space

May 2003
ISBN 0-262-57174-9
5 3/8 x 8, 100 pp., 25 illus.(PAPER)

Janos Bolyai (1802-1860) was a mathematician who changed our fundamental ideas about space. As a teenager he started to explore a set of nettlesome geometrical problems, including Euclid's parallel postulate, and in 1832 he published a brilliant twenty-four-page paper that eventually shook the foundations of the 2000-year-old tradition of Euclidean geometry. Bolyai's "Appendix" (published as just that--an appendix to a much longer mathematical work by his father) set up a series of mathematical proposals whose implications would blossom into the new field of non-Euclidean geometry, providing essential intellectual background for ideas as varied as the theory of relativity and the work of Marcel Duchamp. In this short book, Jeremy Gray explains Bolyai's ideas and the historical context in which they emerged, were debated, and were eventually recognized as a central achievement in the Western intellectual tradition. Intended for nonspecialists, the book includes facsimiles of Bolyai's original paper and the 1898 English translation by G. B. Halstead, both reproduced from copies in the Burndy Library at MIT.

Edited by
E. Boros, Rutgers University, Center for Operations Research, Piscataway, NJ, USA
P.L. Hammer, Rutgers University, Center for Operations Research, Piscataway, NJ, USA

Discrete Optimization
The State of the Art

Topics in Discrete Mathematics, 11

Description

One of the most frequently occurring types of optimization problems involves decision variables which have to take integer values. From a practical point of view, such problems occur in countless areas of management, engineering, administration, etc., and include such problems as location of plants or warehouses, scheduling of aircraft, cutting raw materials to prescribed dimensions, design of computer chips, increasing reliability or capacity of networks, etc. This is the class of problems known in the professional literature as "discrete optimization" problems. While these problems are of enormous applicability, they present many challenges from a computational point of view. This volume is an update on the impressive progress achieved by mathematicians, operations researchers, and computer scientists in solving discrete optimization problems of very large sizes. The surveys in this volume present a comprehensive overview of the state of the art in discrete optimization and are written by the most prominent researchers from all over the world.

This volume describes the tremendous progress in discrete optimization achieved in the last 20 years since the publication of Discrete Optimization '77, Annals of Discrete Mathematics, volumes 4 and 5, 1979 (Elsevier). It contains surveys of the state of the art written by the most prominent researchers in the field from all over the world, and covers topics like neighborhood search techniques, lift and project for mixed 0-1 programming, pseudo-Boolean optimization, scheduling and assignment problems, production planning, location, bin packing, cutting planes, vehicle routing, and applications to graph theory, mechanics, chip design, etc.

Contents

Preface.

Non-standard approaches to integer programming (K. Aardal, R. Weismantel, L.A. Wolsey).
A survey of very large-scale neighborhood search techniques (R.K. Ahuja, O. Ergun, J.B Orlin, A.P. Punnen).
Maximum mean weight cycle in a digraph and minimizing cycle time of a logic chip (C. Albrecht, B. Korte, J. Schietke, J. Vygen).
Lift-and-project for Mixed 0-1 programming: recent progress (E. Balas, M. Perregaard).
Pseudo-Boolean optimization (E. Boros, P.L. Hammer).
Scheduling and constraint propagation (P. Brucker).
Selected topics on assignment problems (R.E. Burkard).
Ideal clutters (G. Cornuejols, B. Guenin).
Production planning problems in printed circuit board assembly (Y. Crama, J. van de Klundert, F.C.R. Spieksma).
Discrete location problems with push-pull objectives (J. Krarup, D. Pisinger, F. Plastria).
Recent advances on two-dimensional bin packing problems (A. Lodi, S. Martello, D. Vigo).
Cutting planes in integer and mixed integer programming (H. Marchand, A. Martin, R. Weismantel, L. Wolsey).
Graph connectivity and its augmentation: applications of MA orderings (H. Nagamochi, T. Ibaraki).
Applications of combinatorics to statics - rigidity of grids (N. Radics, A. Recski).
Models, relaxations and exact approaches for the capacitated vehicle routing problem (P. Toth, D. Vigo).
Semidefinite programming for discrete optimization and matrix completion problems (H. Wolkowicz, M.F. Anjos).
Author index.

Year 2003
Hardbound
ISBN: 0-444-51295-0
588 pages

Edited by
D.N. Shanbhag, University of Sheffield, UK
C.R. Rao, The Pennsylvania State University, USA

Handbook of Statistics 21: Stochastic Processes: Modeling and Simulation

Description

This is a sequel to volume 19 of Handbook of Statistics on Stochastic Processes: Modelling and Simulation. It is concerned mainly with the theme of reviewing and in some cases, unifying with new ideas the different lines of research and developments in stochastic processes of applied flavour. This volume consists of 23 chapters addressing various topics in stochastic processes. These include, among others, those on manufacturing systems, random graphs, reliability, epidemic modelling, self-similar processes, empirical processes, time series models, extreme value theory, applications of Markov chains, modelling with Monte carlo techniques, and stochastic processes in subjects such as engineering, telecommunications, biology, astronomy and chemistry. (A complete list of the topics addressed in the volume is available from the "Contents" of the volume.)

An attempt is made to cover in this volume, as in the case of its predecessor, as many topics as possible. Among various issues considered in this volume, there are those concerned in particular with modelling, simulation techniques and numerical methods concerned with stochastic processes. The scope of the project involving this volume as well as volume 19 is already clarified in the "Preface" of volume 19. The present volume completes the aim of the project, and it should serve as an aid to students, teachers, researchers and practitioners interested in applied stochastic processes.

Year 2003
Hardbound
ISBN: 0-444-50013-8
approx 800 pages