Szymon Dolecki – författare

Ce livre d’analyse est destiné aux étudiants de troisième année de licence de mathématiques. L’auteur traite des connaissances fondamentales sur les espaces métriques et normés, accompagnées toutefois d’informations concises sur l''histoire des concepts et sur les développements récents. Plusieurs aspects sont traités de façon originale, motivée par la recherche de l’auteur (le traitement des suites ou le calcul relationnel). Deux appendices permettent aux étudiants motivés d''approfondir quelques sujets importants (nombres ordinaux, compacité) au-delà du cadre de la licence. Une esquisse de la théorie des ensembles consentira l''utilisation des concepts de relation et de cardinalité. Ensuite, on procède à partir d''une unique abstraction qui nous transporte du cadre des espaces euclidiens, familiers aux étudiants de la Licence 2, dans le domaine des espaces métriques, dont on étudie des classes principales (espaces séparables, compacts, complets et connexes), en découvrant des espaces universels, dont tout espace métrique (respectivement, métrique séparable) est un sous-espace, ou d''autres (ensemble de Cantor), dont tout espace métrique compact est une image continue. L''abstraction de la structure vectorielle permet d''étudier les espaces métriques avec beaucoup plus d''aisance qu''avec des contraintes supplémentaires d''une autre structure. On étudie ensuite les espaces vectoriels avant de les munir des métriques compatibles avec leur structure vectorielle (espaces normés) et d''y ajouter la complétude (espaces de Banach), en profitant des acquis de l''étude des espaces métriques complets. On se focalise enfin sur la classe des espaces munis de produit scalaire qui les rendent complets (espaces de Hilbert), où la notion d''orthogonalité nous approche de nos intuitions initiales des espaces euclidiens, en concluant à l''universalité (parmi les espaces de Hilbert) de l''espace des fonctions carré-sommables.

The 2-yearly French-German Conferences on Optimization review the state-of-the-art and the trends in the field. The proceedings of the Fifth Conference include papers on projective methods in linear programming (special session at the conference), nonsmooth optimization, two-level optimization, multiobjective optimization, partial inverse method, variational convergence, Newton type algorithms and flows and on practical applications of optimization. A. Ioffe and J.-Ph. Vial have contributed survey papers on, respectively second order optimality conditions and projective methods in linear programming.

Topological spaces are a special case of convergence spaces. This textbook introduces topology within a broader context of convergence theory. The title alludes to advantages of the present approach, which is more gratifying than many traditional ones: you travel more comfortably through mathematical landscapes and you see more.The book is addressed both to those who wish to learn topology and to those who, being already knowledgeable about topology, are curious to review it from a different perspective, which goes well beyond the traditional knowledge.Usual topics of classic courses of set-theoretic topology are treated at an early stage of the book — from a viewpoint of convergence of filters, but in a rather elementary way. Later on, most of these facts reappear as simple consequences of more advanced aspects of convergence theory.The mentioned virtues of the approach stem from the fact that the class of convergences is closed under several natural, essential operations, under which the class of topologies is not! Accordingly, convergence theory complements topology like the field of complex numbers algebraically completes the field of real numbers.Convergence theory is intuitive and operational because of appropriate level of its abstraction, general enough to grasp the underlying laws, but not too much in order not to lose intuitive appeal.

This textbook is an alternative to a classical introductory book in point-set topology. The approach, however, is radically different from the classical one. It is based on convergence rather than on open and closed sets. Convergence of filters is a natural generalization of the basic and well-known concept of convergence of sequences, so that convergence theory is more natural and intuitive to many, perhaps most, students than classical topology. On the other hand, the framework of convergence is easier, more powerful and far-reaching which highlights a need for a theory of convergence in various branches of analysis.Convergence theory for filters is gradually introduced and systematically developed. Topological spaces are presented as a special subclass of convergence spaces of particular interest, but a large part of the material usually developed in a topology textbook is treated in the larger realm of convergence spaces.

This textbook is an alternative to a classical introductory book in point-set topology. The approach, however, is radically different from the classical one. It is based on convergence rather than on open and closed sets. Convergence of filters is a natural generalization of the basic and well-known concept of convergence of sequences, so that convergence theory is more natural and intuitive to many, perhaps most, students than classical topology. On the other hand, the framework of convergence is easier, more powerful and far-reaching which highlights a need for a theory of convergence in various branches of analysis.Convergence theory for filters is gradually introduced and systematically developed. Topological spaces are presented as a special subclass of convergence spaces of particular interest, but a large part of the material usually developed in a topology textbook is treated in the larger realm of convergence spaces.

Topological spaces are a special case of convergence spaces. This textbook introduces topology within a broader context of convergence theory. The title alludes to advantages of the present approach, which is more gratifying than many traditional ones: you travel more comfortably through mathematical landscapes and you see more.The book is addressed both to those who wish to learn topology and to those who, being already knowledgeable about topology, are curious to review it from a different perspective, which goes well beyond the traditional knowledge.Usual topics of classic courses of set-theoretic topology are treated at an early stage of the book — from a viewpoint of convergence of filters, but in a rather elementary way. Later on, most of these facts reappear as simple consequences of more advanced aspects of convergence theory.The mentioned virtues of the approach stem from the fact that the class of convergences is closed under several natural, essential operations, under which the class of topologies is not! Accordingly, convergence theory complements topology like the field of complex numbers algebraically completes the field of real numbers.Convergence theory is intuitive and operational because of appropriate level of its abstraction, general enough to grasp the underlying laws, but not too much in order not to lose intuitive appeal.