Abstract Algebra, 3rd Edition

The principal change from the second edition is the addition of Grobner bases to this edition. The basic theory is introduced in a new Section 9.6. Applications to solving systems of polynomial equations (elimination theory) appear at the end of this section, rounding it out as a self-contained foundation in the topic. Additional applications and examples are then woven into the treatment of affine algebraic sets and Jt-algebra homo-morphisms in Chapter 15. Although the theory in the latter chapter remains independent of Grobner bases, the new applications, examples and computational techniques significantly enhance the development, and we recommend that Section 9.6 be read either as a segue to or in parallel with Chapter 15. A wealth of exercises involving Grobner bases, both computational and theoretical in nature, have been added in Section 9.6 and Chapter 15. Preliminary exercises on Grobner bases can (and should, as an aid to understanding the algorithms) be done by hand, but more extensive computations, and in particular most of the use of Grobner bases in the exercises in Chapter 15, will likely require computer assisted computation. Preface Preliminaries Basics Properties of the Integers Z/nZ: The Integers Modulo n Group Theory Introduction to Groups Basic Axioms and Examples Dihedral Groups Symmetric Groups Matrix Groups The Quaternion Group Homomorphisms and Isomorphisms Group Actions Subgroups Definitions and Examples Centralizers and Normalizers, Stabilizers and Kernels Cyclic Groups and Cyclic Subgroups Subgroups Generated by Subsets of a Group The Lattice of Subgroups of a Group Quotient Groups and Homomorphisms Definitions and Examples More on Cosets and Lagrange's Theorem The Isomorphism Theorems Composition Series and the Holder Program Transpositions and the Alternating Group Group Actions Group Actions and Permutation Representations Groups Acting on Themselves by Left Multiplication-Cayley's Theorem Groups Acting on Themselves by Conjugation-The Class Equation Automorphism The Sylow Theorems The Simplicity of An Direct and Semidirect Products and Abelian Groups Direct Products The Fundamental Theorem of Finitely Generated Ableian Groups Table of Groups of Small Order Recognizing Direct Products Semidirect Products Further Topics in Group Theory p-groups, Nilpotent Groups, and Solvable Groups Applications in Groups of Medium Order A Word on Free Groups Ring Theory Introduction to Rings Basic Definitions and Exmaples Examples: Polynomial Rings, Matri Rings, and Group Rings Ring Homomorphisms and Quotinet Rings Properties of Ideals Rings of fractions The Chinese Remainder Theorem Euclidean Domains, Principla Ideal Domains and Unique Factorization Domains Euclidean Domains Principal Ideal Domains (P.I.D.s) Unique Factorization Domains (U.F.D.s) Polynomial Rings Definitions and Basic Properties Polynomial Rings over Fields I Polynomial Rings that are Unique Factorization Domains Irreducibility Criteria Polynomial rings over Fields II Polynomials in Several Variables over a Field and Grobner Bases Modules and Vector Spaces Introduction to Module Theory Basic Definitions and Examples Quotient Modules and Module Homomorphisms Generation of Modules, Direct Sums, and Free Modules Tensor Product of Modules Exact Sequences - Projective, Injective, and Flat Modules vector Spaces Definitions and Basic Theory The Matrix of a Linear Transformation Dual Vector Spaces Determinants Tensor Algebras, Symmetric and Exterior Algebras Modules over Principal Ideal Domains The Basic Theory The Rational Canonical From The Jordan Canonical From Field Theory Basic Theory of field Extensions Algebraic extensions Classical Straightedge and Compass Constructions Splitting Fields and Algebraic Closures Separable and Inseparable Extensions Cyclotomic Polynomials and Extensions Galios Theory Basic Definitions The Fundamental Theorem of Galios Theory Finite Fields Composite Extensions and Simple Extensions Cyclotomic Extensions and Albelian Extensions over Q Galois Groups of Polynomials Solvable and Radical Extensions: Insolvability of the Quintic Computation of the Galois Groups over Q Transcendental Extensions, Inseparable Extensions, Infinite Galois Groups An Introduction to Comutative Rings, Algebraic Geometry, and Homological Algebra Commutative Rings and Algebraic Geometry Noetherian Rings and Affine Algebraic Sets Radicals and Affine Varieties Integral Extensions and Hilbert's Nullstellensatz Localization The Prime Spectrum of a Ring Artinian Rings, Discrete Valuation Rings, and Dedekind Domains Artinian Rings Discrete Valuation Rings Dedekind Domains Introduction to Homological Algebra and Group Cohomology Introduction to Homological Algebra - Ext and Tor The Cohomology of Groups Crossed Homomorphisms and H1(G, A) Group Extensions, Factor Sets and H2(G, A) Introduction to the Representation Theory of Finite Groups Representation Theory and Character Theory Linear Actions and Modules over Group Rings Wedderburn's Theorem and Some Consequences Character Theory and the Orthogonality Relations Examples and Applications of Character Theory Characters of Groups of Small Order Theorems of Burnside and Hall Introduction to the Theory of Induced Characters Cartesian Products and Zorn's Lemma Category Theory Index This Book Is Designed To Give The Reader Insight Into The Power And Beauty That Accrues From A Rich Interplay Between Different Areas Of Mathematics. The Book Carefully Develops The Theory Of Different Algebraic Structures, Beginning From Basic Definitions To Some In-depth Results, Using Numerous Examples And Exercises To Aid The Reader's Understanding. In This Way, Readers Gain An Appreciation For How Mathematical Structures And Their Interplay Lead To Powerful Results And Insights In A Number Of Different Settings. Part. 1. Group Theory: Introduction To Groups -- Subgroups -- Quotient Groups And Homomorphisms -- Group Actions -- Direct And Semidirect Products And Abelian Groups -- Further Topics In Group Theory -- Part 2. Ring Theory: Introduction To Rings -- Euclidean Domains, Principal Ideal Domains And Unique Factorization Domains -- Polynomial Rings -- Part 3. Modules And Vector Spaces: Introduction To Module Theory -- Vector Spaces -- Modules Over Principal Ideal Domains -- Part. 4. Field Theory And Galois Theory: Field Theory -- Galois Theory -- Part 5. An Introduction To Commutative Rings, Algebraic Geometry, And Homological Algebra: Commutative Rings And Algebraic Geometry -- Artinian Rings, Discrete Valuation Rings, And Dedekind Domains -- Introduction To Homological Algebra And Group Cohomology -- Part 6. Introduction To The Representation Theory Of Finite Groups: Representation Theory And Character Theory -- Examples And Applications Of Character Theory. David S. Dummit, Richard M. Foote. Includes Index. Widely acclaimed algebra text. This book is designed to give the reader insight into the power and beauty that accrues from a rich interplay between different areas of mathematics. The book carefully develops the theory of different algebraic structures, beginning from basic definitions to some in-depth results, using numerous examples and exercises to aid the reader's understanding. In this way, readers gain an appreciation for how mathematical structures and their interplay lead to powerful results and insights in a number of different settings. * The emphasis throughout has been to motivate the introduction and development of important algebraic concepts using as many examples as possible.