: Antonio Machì
: Groups An Introduction to Ideas and Methods of the Theory of Groups
: Springer Verlag Italia
: 9788847024212
: 1
: CHF 37.80
:
: Arithmetik, Algebra
: English
: 385
: DRM
: PC/MAC/eReader/Tablet
: PDF
Groups are a means of classification, via the group action on a set, but also the object of a classification. How many groups of a given type are there, and how can they be described? Hölder's program for attacking this problem in the case of finite groups is a sort of leitmotiv throughout the text. Infinite groups are also considered, with particular attention to logical and decision problems. Abelian, nilpotent and solvable groups are studied both in the finite and infinite case. Permutation groups and are treated in detail; their relationship with Galois theory is often taken into account. The last two chapters deal with the representation theory of finite group and the cohomology theory of groups; the latter with special emphasis on the extension problem. The sections are followed by exercises; hints to the solution are given, and for most of them a complete solution is provided.
Preface5
Notation8
Table of Contents 9
1 Introductory Notions12
1.1 Definitions and First Theorems12
1.2 Cosets and Lagrange’s Theorem35
1.3 Automorphisms45
2 Normal Subgroups, Conjugation and Isomorphism Theorems49
2.1 Product of Subgroups49
2.2 Normal Subgroups and Quotient Groups50
2.3 Conjugation60
2.4 Normalizers and Centralizers of Subgroups69
2.5 H¨older’s Program73
2.6 Direct Products77
2.7 Semidirect Products83
2.8 Symmetric and Alternating Groups88
2.9 The Derived Group92
3 Group Actions and Permutation Groups97
3.1 Group actions97
3.2 The Sylow Theorem109
3.3 Burnside’s Formula and Permutation Characters127
3.4 Induced Actions135
3.5 Permutations Commuting with an Action138
3.6 Automorphisms of Symmetric Groups144
3.7 Permutations and Inversions146
3.8 Some Simple Groups153
3.8.1 The Simple Group of Order 168153
3.8.2 Projective Special Linear Groups157
4 Generators and Relations164
4.1 Generating Sets164
4.2 The Frattini Subgroup169
4.3 Finitely Generated Abelian Groups173
4.4 Free abelian groups179
4.5 Projective and Injective Abelian Groups187
4.6 Characters of Abelian Groups190
4.7 Free Groups192
4.8 Relations197
4.8.1 Relations and simple Groups201
4.9 Subgroups of Free Groups203
4.10 The Word Problem207
4.11 Residual Properties209
5 Nilpotent Groups and Solvable Groups214
5.1 Central Series and Nilpotent Groups214
5.2 p-Nilpotent Groups232
5.3 Fusion238
5.4 Fixed-Point-Free Automorphisms and Frobenius Groups241
5.5 Solvable Groups246
6 Representations262
6.1 Definitions and examples262
6.1.1 Maschke’s Theorem266
6.2 Characters268
6.3 The Character Table284
6.3.1 Burnside’s Theorem and Frobenius Theorem289
6.3.2 Topological Groups294
7 Extensions and Cohomology298
7.1 Crossed Homomorphisms298
7.2 The First Cohomology Group301
7.3 The Second Cohomology Group310
7.3.1 H1 and Extensions316
7.3.2 H2(p,A) for p Finite Cyclic317
7.4 The Schur Multiplier321
7.4.1 Projective Representations322
7.4.2 Covering Groups324
7.4.3 M(p) and Presentations of p329
8 Solution to the exercises335
8.1 Chapter 1335
8.2 Chapter 2337
8.3 Chapter 3343
8.4 Chapter 4354
8.5 Chapter 5359
8.6 Chapter 6366
References371
Index373