Homology

Biography of Saunders Mac Lane Saunders Mac Lane was born on August 4, 1909 in Connecticut. He studied at Yale University and then at the University of Chicago and at Göttingen, where he received the D.Phil. in 1934. He has tought at Harvard, Cornell and the University of Chicago. Mac Lane's initial research was in logic and in algebraic number theory (valuation theory). With Samuel Eilenberg he published fifteen papers on algebraic topology. A number of them involved the initial steps in the cohomology of groups and in other aspects of homological algebra - as well as the discovery of category theory. His famous and undergraduate textbook Survey of modern algebra, written jointly with G. Birkhoff, has remained in print for over 50 years. Mac Lane is also the author of several other highly successful books.

I. Modules, Diagrams, and Functors.- 1. The Arrow Notation.- 2. Modules.- 3. Diagrams.- 4. Direct Sums.- 5. Free and Projective Modules.- 6. The Functor Horn.- 7. Categories.- 8. Functors.- II. Homology of Complexes.- 1. Differential Groups.- 2. Complexes.- 3. Cohomology.- 4. The Exact Homology Sequence.- 5. Some Diagram Lemmas.- 6. Additive Relations.- 7. Singular Homology.- 8. Homotopy.- 9. Axioms for Homology.- III. Extensions and Resolutions.- 1. Extensions of Modules.- 2. Addition of Extensions.- 3. Obstructions to the Extension of Homomorphisms.- 4. The Universal Coefficient Theorem for Cohomology.- 5. Composition of Extensions.- 6. Resolutions.- 7. Injective Modules.- 8. Injective Resolutions.- 9. Two Exact Sequences for Extn.- 10. Axiomatic Description of Ext.- 11. The Injective Envelope.- IV. Cohomology of Groups.- 1. The Group Ring.- 2. Crossed Homomorphisms.- 3. Group Extensions.- 4. Factor Sets.- 5. The Bar Resolution.- 6. The Characteristic Class of a Group Extension.- 7. Cohomology of Cyclic and Free Groups.- 8. Obstructions to Extensions.- 9. Realization of Obstructions.- 10. SCHUR'S Theorem.- 11. Spaces with Operators.- V. Tensor and Torsion Products.- 1. Tensor Products.- 2. Modules over Commutative Rings.- 3. Bimodules.- 4. Dual Modules.- 5. Right Exactness of Tensor Products.- 6. Torsion Products of Groups.- 7. Torsion Products of Modules.- 8. Torsion Products by Resolutions.- 9. The Tensor Product of Complexes.- 10. The KÜNNETH Formula.- 11. Universal Coefficient Theorems.- VI. Types of Algebras.- 1. Algebras by Diagrams.- 2. Graded Modules.- 3. Graded Algebras.- 4. Tensor Products of Algebras.- 5. Modules over Algebras.- 6. Cohomology of free Abelian Groups.- 7. Differential Graded Algebras.- 8. Identities on Horn and ?.- 9. Coalgebras and HOPFAlgebras.- VII. Dimension.- 1. Homological Dimension.- 2. Dimensions in Polynomial Rings.- 3. Ext and Tor for Algebras.- 4. Global Dimensions of Polynomial Rings.- 5. Separable Algebras.- 6. Graded Syzygies.- 7. Local Rings.- VIII. Products.- 1. Homology Products.- 2. The Torsion Product of Algebras.- 3. A Diagram Lemma.- 4. External Products for Ext.- 5. Simplicial Objects.- 6. Normalization.- 7. Acyclic Models.- 8. The EILENBERG-ZILBER Theorem.- 9. Cup Products.- IX. Relative Homological Algebra.- 1. Additive Categories.- 2. Abelian Categories.- 3. Categories of Diagrams.- 4. Comparison of Allowable Resolutions.- 5. Relative Abelian Categories.- 6. Relative Resolutions.- 7. The Categorical Bar Resolution.- 8. Relative Torsion Products.- 9. Direct Products of Rings.- X. Cohomology of Algebraic Systems.- 1. Introduction.- 2. The Bar Resolution for Algebras.- 3. The Cohomology of an Algebra.- 4. The Homology of an Algebra.- 5. Homology of Groups and Monoids.- 6. Ground Ring Extensions and Direct Products.- 7. Homology of Tensor Products.- 8. The Case of Graded Algebras.- 9. Complexes of Complexes.- 10. Resolutions and Constructions.- 11. Two-stage Cohomology of DGA-Algebras.- 12. Cohomology of Commutative DGA-Algebras.- 13. Homology of Algebraic Systems.- XI. Spectral Sequences.- 1. Spectral Sequences.- 2. Fiber Spaces.- 3. Filtered Modules.- 4. Transgression.- 5. Exact Couples.- 6. Bicomplexes.- 7. The Spectral Sequence of a Covering.- 8. Cohomology Spectral Sequences.- 9. Restriction, Inflation, and Connection.- 10. The Lyndon Spectral Sequence.- 11. The Comparison Theorem.- XII. Derived Functors.- 1. Squares.- 2. Subobjects and Quotient Objects.- 3. Diagram Chasing.- 4. Proper Exact Sequences.- 5. Ext without Projectives.- 6. The Category of Short Exact Sequences.- 7. Connected Pairs of Additive Functors.- 8. Connected Sequences of Functors.- 9. Derived Functors.- 10. Products by Universality.- 11. Proper Projective Complexes.- 12. The Spectral KÜNNETH Formula.- List of Standard Symbols.