S.P. Novikov – författare

Up until recently, Riemannian geometry and basic topology were not included, even by departments or faculties of mathematics, as compulsory subjects in a university-level mathematical education. The standard courses in the classical differential geometry of curves and surfaces which were given instead (and still are given in some places) have come gradually to be viewed as anachronisms. However, there has been hitherto no unanimous agreement as to exactly how such courses should be brought up to date, that is to say, which parts of modern geometry should be regarded as absolutely essential to a modern mathematical education, and what might be the appropriate level of abstractness of their exposition. The task of designing a modernized course in geometry was begun in 1971 in the mechanics division of the Faculty of Mechanics and Mathematics of Moscow State University. The subject-matter and level of abstractness of its exposition were dictated by the view that, in addition to the geometry of curves and surfaces, the following topics are certainly useful in the various areas of application of mathematics (especially in elasticity and relativity, to name but two), and are therefore essential: the theory of tensors (including covariant differentiation of them); Riemannian curvature; geodesics and the calculus of variations (including the conservation laws and Hamiltonian formalism); the particular case of skew-symmetric tensors (i. e.

Over the past fifteen years, the geometrical and topological methods of the theory of manifolds have as- sumed a central role in the most advanced areas of pure and applied mathematics as well as theoretical physics. The three volumes of Modern Geometry - Methods and Applications contain a concrete exposition of these methods together with their main applications in mathematics and physics. This third volume, presented in highly accessible languages, concentrates in homology theory. It contains introductions to the contemporary methods for the calculation of homology groups and the classification of manifesto. Both scientists and students of mathematics as well as theoretical physics will find this book to be a valuable reference and text.

This is the first volume of a three-volume introduction to modern geometry, with emphasis on applications to other areas of mathematics and theoretical physics. Topics covered include tensors and their differential calculus, the calculus of variations in one and several dimensions, and geometric field theory. This material is explained in as simple and concrete a language as possible, in a terminology acceptable to physicists. The text for the second edition has been substantially revised.

One service mathematics has rendered the 'Et moi, ..., si j'avait su comment en revenir, je n'y serais point aile.' human race. It has put common sense back Jules Verne where it belongs, on the topmost shelf next to the dusty canister labelled 'discarded n- sense'. The series is divergent; therefore we may be able to do something with it. Eric T. Bell O. Heaviside Matht"natics is a tool for thought. A highly necessary tool in a world where both feedback and non- linearities abound. Similarly, all kinds of parts of mathematics seNe as tools for other parts and for other sciences. Applying a simple rewriting rule to the quote on the right above one finds such statements as: 'One service topology has rendered mathematical physics ...'; 'One service logic has rendered com- puter science ...'; 'One service category theory has rendered mathematics ...'. All arguably true. And all statements obtainable this way form part of the raison d'etre of this series.

Up until recently, Riemannian geometry and basic topology were not included, even by departments or faculties of mathematics, as compulsory subjects in a university-level mathematical education. The standard courses in the classical differential geometry of curves and surfaces which were given instead (and still are given in some places) have come gradually to be viewed as anachronisms. However, there has been hitherto no unanimous agreement as to exactly how such courses should be brought up to date, that is to say, which parts of modern geometry should be regarded as absolutely essential to a modern mathematical education, and what might be the appropriate level of abstractness of their exposition. The task of designing a modernized course in geometry was begun in 1971 in the mechanics division of the Faculty of Mechanics and Mathematics of Moscow State University. The subject-matter and level of abstractness of its exposition were dictated by the view that, in addition to the geometry of curves and surfaces, the following topics are certainly useful in the various areas of application of mathematics (especially in elasticity and relativity, to name but two), and are therefore essential: the theory of tensors (including covariant differentiation of them); Riemannian curvature; geodesics and the calculus of variations (including the conservation laws and Hamiltonian formalism); the particular case of skew-symmetric tensors (i. e.

Up until recently, Riemannian geometry and basic topology were not included, even by departments or faculties of mathematics, as compulsory subjects in a university-level mathematical education. The standard courses in the classical differential geometry of curves and surfaces which were given instead (and still are given in some places) have come gradually to be viewed as anachronisms. However, there has been hitherto no unanimous agreement as to exactly how such courses should be brought up to date, that is to say, which parts of modern geometry should be regarded as absolutely essential to a modern mathematical education, and what might be the appropriate level of abstractness of their exposition. The task of designing a modernized course in geometry was begun in 1971 in the mechanics division of the Faculty of Mechanics and Mathematics of Moscow State University. The subject-matter and level of abstractness of its exposition were dictated by the view that, in addition to the geometry of curves and surfaces, the following topics are certainly useful in the various areas of application of mathematics (especially in elasticity and relativity, to name but two), and are therefore essential: the theory of tensors (including covariant differentiation of them); Riemannian curvature; geodesics and the calculus of variations (including the conservation laws and Hamiltonian formalism); the particular case of skew-symmetric tensors (i. e.

This is the first volume of a three-volume introduction to modern geometry, with emphasis on applications to other areas of mathematics and theoretical physics. Topics covered include tensors and their differential calculus, the calculus of variations in one and several dimensions, and geometric field theory. This material is explained in as simple and concrete a language as possible, in a terminology acceptable to physicists. The text for the second edition has been substantially revised.

Over the past fifteen years, the geometrical and topological methods of the theory of manifolds have as- sumed a central role in the most advanced areas of pure and applied mathematics as well as theoretical physics. The three volumes of Modern Geometry - Methods and Applications contain a concrete exposition of these methods together with their main applications in mathematics and physics. This third volume, presented in highly accessible languages, concentrates in homology theory. It contains introductions to the contemporary methods for the calculation of homology groups and the classification of manifesto. Both scientists and students of mathematics as well as theoretical physics will find this book to be a valuable reference and text.

manifolds, transformation groups, and Lie algebras, as well as the basic concepts of visual topology. It was also agreed that the course should be given in as simple and concrete a language as possible, and that wherever practic­ able the terminology should be that used by physicists. Thus it was along these lines that the archetypal course was taught. It was given more permanent form as duplicated lecture notes published under the auspices of Moscow State University as: Differential Geometry, Parts I and II, by S. P. Novikov, Division of Mechanics, Moscow State University, 1972. Subsequently various parts of the course were altered, and new topics added. This supplementary material was published (also in duplicated form) as Differential Geometry, Part III, by S. P. Novikov and A. T. Fomenko, Division of Mechanics, Moscow State University, 1974. The present book is the outcome of a reworking, re-ordering, and ex­ tensive elaboration of the above-mentioned lecture notes. It is the authors'' view that it will serve as a basic text from which the essentials for a course in modern geometry may be easily extracted. To S. P. Novikov are due the original conception and the overall plan of the book. The work of organizing the material contained in the duplicated lecture notes in accordance with this plan was carried out by B. A. Dubrovin.

Introduction In the present essay, we attempt to convey some idea of the skeleton of topology, and of various topological concepts. It must be said at once that, apart from the necessary minimum, the subject-matter of this survey does not indude that subdiscipline known as "general topology" - the theory of general spaces and maps considered in the context of set theory and general category theory. (Doubtless this subject will be surveyed in detail by others. ) With this qualification, it may be daimed that the "topology" dealt with in the present survey is that mathematieal subject whieh in the late 19th century was called Analysis Situs, and at various later periods separated out into various subdisciplines: "Combinatorial topology", "Algebraic topology", "Differential (or smooth) topology", "Homotopy theory", "Geometrie topology". With the growth, over a long period of time, in applications of topology to other areas of mathematics, the following further subdisciplines crystallizedout: the global calculus of variations, global geometry, the topology of Lie groups and homogeneous spaces, the topology of complex manifolds and alge­ braic varieties, the qualitative (topologieal) theory of dynamical systems and foliations, the topology of elliptic and hyperbolic partial differential equations. Finally, in the 1970s and 80s, a whole complex of applications of topologie al methods was made to problems of modern physiesj in fact in several instances it would have been impossible to understand the essence of the real physical phenomena in question without the aid of concepts from topology.

This book is another volume in the successful subseries "Dynamical Systems" of the Encyclopaedia of Mathematical Sciences. It focuses on new developments in the field of integrable systems and it provides a unique and comprehensive survey on new differential geometric and Lie-algebraic methods. Since other literature on these topics is often rather unreadable, this volume will be an indispensable guide to the current research which no mathematician or theoretical physicist who is interested in this field can do without.

to Homotopy Theory O. Ya. Viro, D. B. Fuchs Translated from the Russian by C. J. Shaddock Contents Chapter 1. Basic Concepts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 § 1. Terminology and Notations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 1. 1. Set Theory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 1. 2. Logical Equivalence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 1. 3. Topological Spaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 1. 4. Operations on Topological Spaces . . . . . . . . . . . . . . . . . . . . . . . . . 5 1. 5. Operations on Pointed Spaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 §2. Homotopy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 2. 1. Homotopies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . 10 2. 2. Paths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 2. 3. Homotopy as a Path . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 2. 4. Homotopy Equivalence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 2. 5. Retractions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 2. 6. Deformation Retractions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 2. 7. Relative Homotopies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 2. 8. k-connectedness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 2. 9. Borsuk Pairs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 2. 10. CNRS Spaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 2. 11. Homotopy Properties of Topological Constructions . . . . . . . . . . . 15 2. 12. Natural Group Structures on Sets of Homotopy Classes . . . . . . . . 16 §3. Homotopy Groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 3. 1. Absolute Homotopy Groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 2 O. Ya. Viro, D. B. Fuchs 3. 2. Digression: Local Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 3. 3. Local Systems of Homotopy Groups of a Topological Space . . . . 23 3. 4. Relative Homotopy Groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 3. 5. The Homotopy Sequence of a Pair . . . . . . . . . . . . . . . . . . . . . . . . . 28 3. 6. Splitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 3. 7. The Homotopy Sequence of a Triple . . . . . . . . . . . . . . . . . . . . . . . 32 Chapter 2. Bundle Techniques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . 33 §4. Bundles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 4. 1. General Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 4. 2. Locally Trivial Bundles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 4. 3. Serre Bundles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 4. 4. Bundles of Spaces of Maps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 §5. Bundles and Homotopy Groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 5. 1. The Local System of Homotopy Groups of the Fibres of a Serre Bundle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

From the reviews of the first edition:"... In general the articles ... are well written in a style that enables one to grasp the ideas. The actual style is a readable mix of the important results, outlines of proofs and complete proofs when it does not take too long together with readable explanations of what is going on. Also very useful are the large lists of references which are important not only for their mathematical content but also because the references given also contain articles in the Soviet literature which may not be familiar or possibly accessible to readers."New Zealand Math. Soc. Newsletter 1991"... Here ... a wealth of material is displayed for us, too much to even indicate in a review. ... Your reviewer was very impressed by the contents of both volumes (EMS 2 and 4), recommending them without any restriction. As far as he could judge, most presentations seem fairly complete..."Mededelingen van het Wiskundig genootshap 1992

Introduction In the present essay, we attempt to convey some idea of the skeleton of topology, and of various topological concepts. It must be said at once that, apart from the necessary minimum, the subject-matter of this survey does not indude that subdiscipline known as "general topology" - the theory of general spaces and maps considered in the context of set theory and general category theory. (Doubtless this subject will be surveyed in detail by others. ) With this qualification, it may be daimed that the "topology" dealt with in the present survey is that mathematieal subject whieh in the late 19th century was called Analysis Situs, and at various later periods separated out into various subdisciplines: "Combinatorial topology", "Algebraic topology", "Differential (or smooth) topology", "Homotopy theory", "Geometrie topology". With the growth, over a long period of time, in applications of topology to other areas of mathematics, the following further subdisciplines crystallizedout: the global calculus of variations, global geometry, the topology of Lie groups and homogeneous spaces, the topology of complex manifolds and alge­ braic varieties, the qualitative (topologieal) theory of dynamical systems and foliations, the topology of elliptic and hyperbolic partial differential equations. Finally, in the 1970s and 80s, a whole complex of applications of topologie al methods was made to problems of modern physiesj in fact in several instances it would have been impossible to understand the essence of the real physical phenomena in question without the aid of concepts from topology.

This book is another volume in the successful subseries "Dynamical Systems" of the Encyclopaedia of Mathematical Sciences. It focuses on new developments in the field of integrable systems and it provides a unique and comprehensive survey on new differential geometric and Lie-algebraic methods. Since other literature on these topics is often rather unreadable, this volume will be an indispensable guide to the current research which no mathematician or theoretical physicist who is interested in this field can do without.

to Homotopy Theory O. Ya. Viro, D. B. Fuchs Translated from the Russian by C. J. Shaddock Contents Chapter 1. Basic Concepts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 § 1. Terminology and Notations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 1. 1. Set Theory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 1. 2. Logical Equivalence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 1. 3. Topological Spaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 1. 4. Operations on Topological Spaces . . . . . . . . . . . . . . . . . . . . . . . . . 5 1. 5. Operations on Pointed Spaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 §2. Homotopy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 2. 1. Homotopies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . 10 2. 2. Paths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 2. 3. Homotopy as a Path . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 2. 4. Homotopy Equivalence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 2. 5. Retractions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 2. 6. Deformation Retractions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 2. 7. Relative Homotopies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 2. 8. k-connectedness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 2. 9. Borsuk Pairs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 2. 10. CNRS Spaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 2. 11. Homotopy Properties of Topological Constructions . . . . . . . . . . . 15 2. 12. Natural Group Structures on Sets of Homotopy Classes . . . . . . . . 16 §3. Homotopy Groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 3. 1. Absolute Homotopy Groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 2 O. Ya. Viro, D. B. Fuchs 3. 2. Digression: Local Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 3. 3. Local Systems of Homotopy Groups of a Topological Space . . . . 23 3. 4. Relative Homotopy Groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 3. 5. The Homotopy Sequence of a Pair . . . . . . . . . . . . . . . . . . . . . . . . . 28 3. 6. Splitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 3. 7. The Homotopy Sequence of a Triple . . . . . . . . . . . . . . . . . . . . . . . 32 Chapter 2. Bundle Techniques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . 33 §4. Bundles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 4. 1. General Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 4. 2. Locally Trivial Bundles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 4. 3. Serre Bundles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 4. 4. Bundles of Spaces of Maps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 §5. Bundles and Homotopy Groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 5. 1. The Local System of Homotopy Groups of the Fibres of a Serre Bundle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

From the reviews of the first edition:"... In general the articles ... are well written in a style that enables one to grasp the ideas. The actual style is a readable mix of the important results, outlines of proofs and complete proofs when it does not take too long together with readable explanations of what is going on. Also very useful are the large lists of references which are important not only for their mathematical content but also because the references given also contain articles in the Soviet literature which may not be familiar or possibly accessible to readers."New Zealand Math. Soc. Newsletter 1991"... Here ... a wealth of material is displayed for us, too much to even indicate in a review. ... Your reviewer was very impressed by the contents of both volumes (EMS 2 and 4), recommending them without any restriction. As far as he could judge, most presentations seem fairly complete..."Mededelingen van het Wiskundig genootshap 1992

From the reviews of the first edition:"... In general the articles ... are well written in a style that enables one to grasp the ideas. The actual style is a readable mix of the important results, outlines of proofs and complete proofs when it does not take too long together with readable explanations of what is going on. Also very useful are the large lists of references which are important not only for their mathematical content but also because the references given also contain articles in the Soviet literature which may not be familiar or possibly accessible to readers."New Zealand Math. Soc. Newsletter 1991"... Here ... a wealth of material is displayed for us, too much to even indicate in a review. ... Your reviewer was very impressed by the contents of both volumes (EMS 2 and 4), recommending them without any restriction. As far as he could judge, most presentations seem fairly complete..."Mededelingen van het Wiskundig genootshap 1992

This book takes a snapshot of the mathematical foundations of classical and quantum mechanics from a contemporary mathematical viewpoint. It covers a number of important recent developments in dynamical systems and mathematical physics and places them in the framework of the more classical approaches; the presentation is enhanced by many illustrative examples concerning topics which have been of especial interest to workers in the field, and by sketches of the proofs of the major results. The comprehensive bibliographies are designed to permit the interested reader to retrace the major stages in the development of the field if he wishes. Not so much a detailed textbook for plodding students, this volume, like the others in the series, is intended to lead researchers in other fields and advanced students quickly to an understanding of the ''state of the art'' in this area of mathematics. As such it will serve both as a basic reference work on important areas of mathematical physics as they stand today, and as a good starting point for further, more detailed study for people new to this field.

This book is another volume in the successful subseries "e;Dynamical Systems"e; of the Encyclopaedia of Mathematical Sciences. It focuses on new developments in the field of integrable systems and it provides a unique and comprehensive survey on new differential geometric and Lie-algebraic methods. Since other literature on these topics is often rather unreadable, this volume will be an indispensable guide to the current research which no mathematician or theoretical physicist who is interested in this field can do without.

Introduction In the present essay, we attempt to convey some idea of the skeleton of topology, and of various topological concepts. It must be said at once that, apart from the necessary minimum, the subject-matter of this survey does not indude that subdiscipline known as "general topology" - the theory of general spaces and maps considered in the context of set theory and general category theory. (Doubtless this subject will be surveyed in detail by others. ) With this qualification, it may be daimed that the "topology" dealt with in the present survey is that mathematieal subject whieh in the late 19th century was called Analysis Situs, and at various later periods separated out into various subdisciplines: "Combinatorial topology", "Algebraic topology", "Differential (or smooth) topology", "Homotopy theory", "Geometrie topology". With the growth, over a long period of time, in applications of topology to other areas of mathematics, the following further subdisciplines crystallizedout: the global calculus of variations, global geometry, the topology of Lie groups and homogeneous spaces, the topology of complex manifolds and alge­ braic varieties, the qualitative (topologieal) theory of dynamical systems and foliations, the topology of elliptic and hyperbolic partial differential equations. Finally, in the 1970s and 80s, a whole complex of applications of topologie al methods was made to problems of modern physiesj in fact in several instances it would have been impossible to understand the essence of the real physical phenomena in question without the aid of concepts from topology.

to Homotopy Theory O. Ya. Viro, D. B. Fuchs Translated from the Russian by C. J. Shaddock Contents Chapter 1. Basic Concepts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 § 1. Terminology and Notations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 1. 1. Set Theory . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 1. 2. Logical Equivalence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 1. 3. Topological Spaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5 1. 4. Operations on Topological Spaces . . . . . . . . . . . . . . . . . . . . . . . . . 5 1. 5. Operations on Pointed Spaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 §2. Homotopy . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 2. 1. Homotopies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . 10 2. 2. Paths . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 2. 3. Homotopy as a Path . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 2. 4. Homotopy Equivalence . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 2. 5. Retractions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 2. 6. Deformation Retractions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 2. 7. Relative Homotopies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 2. 8. k-connectedness . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 2. 9. Borsuk Pairs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 2. 10. CNRS Spaces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 2. 11. Homotopy Properties of Topological Constructions . . . . . . . . . . . 15 2. 12. Natural Group Structures on Sets of Homotopy Classes . . . . . . . . 16 §3. Homotopy Groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 3. 1. Absolute Homotopy Groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 2 O. Ya. Viro, D. B. Fuchs 3. 2. Digression: Local Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 3. 3. Local Systems of Homotopy Groups of a Topological Space . . . . 23 3. 4. Relative Homotopy Groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 3. 5. The Homotopy Sequence of a Pair . . . . . . . . . . . . . . . . . . . . . . . . . 28 3. 6. Splitting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 3. 7. The Homotopy Sequence of a Triple . . . . . . . . . . . . . . . . . . . . . . . 32 Chapter 2. Bundle Techniques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . 33 §4. Bundles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 4. 1. General Definitions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 4. 2. Locally Trivial Bundles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 4. 3. Serre Bundles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 4. 4. Bundles of Spaces of Maps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 §5. Bundles and Homotopy Groups . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38 5. 1. The Local System of Homotopy Groups of the Fibres of a Serre Bundle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

One service mathematics has rendered the 'Et moi, ..., si j'avait su comment en revenir, je n'y serais point aile.' human race. It has put common sense back Jules Verne where it belongs, on the topmost shelf next to the dusty canister labelled 'discarded n- sense'. The series is divergent; therefore we may be able to do something with it. Eric T. Bell O. Heaviside Matht"natics is a tool for thought. A highly necessary tool in a world where both feedback and non- linearities abound. Similarly, all kinds of parts of mathematics seNe as tools for other parts and for other sciences. Applying a simple rewriting rule to the quote on the right above one finds such statements as: 'One service topology has rendered mathematical physics ...'; 'One service logic has rendered com- puter science ...'; 'One service category theory has rendered mathematics ...'. All arguably true. And all statements obtainable this way form part of the raison d'etre of this series.