Book contents
- Frontmatter
- Contents
- Introduction
- 1 Groups and semigroups: connections and contrasts
- 2 Toward the classification of s-arc transitive graphs
- 3 Non-cancellation group computation for some finitely generated nilpotent groups
- 4 Permutation and quasi-permutation representations of the Chevalley groups
- 5 The shape of solvable groups with odd order
- 6 Embedding in finitely presented lattice-ordered groups: explicit presentations for constructions
- 7 A note on abelian subgroups of p-groups
- 8 On kernel flatness
- 9 On proofs in finitely presented groups
- 10 Computing with 4-Engel groups
- 11 On the size of the commutator subgroup in finite groups
- 12 Groups of infinite matrices
- 13 Triply factorised groups and nearrings
- 14 On the space of cyclic trigonal Riemann surfaces of genus 4
- 15 On simple Kn-groups for n = 5, 6
- 16 Products of Sylow subgroups and the solvable radical
- 17 On commutators in groups
- 18 Inequalities for the Baer invariant of finite groups
- 19 Automorphisms with centralizers of small rank
- 20 2-signalizers and normalizers of Sylow 2-subgroups in finite simple groups
- 21 On properties of abnormal and pronormal subgroups in some infinite groups
- 22 P-localizing group extensions
- 23 On the n-covers of exceptional groups of Lie type
- 24 Positively discriminating groups
- 25 Automorphism groups of some chemical graphs
- 26 On c-normal subgroups of some classes of finite groups
- 27 Fong characters and their fields of values
- 28 Arithmetical properties of finite groups
- 29 On prefrattini subgroups of finite groups: a survey
- 30 Frattini extensions and class field theory
- 31 The nilpotency class of groups with fixed point free automorphisms of prime order
1 - Groups and semigroups: connections and contrasts
Published online by Cambridge University Press: 20 April 2010
- Frontmatter
- Contents
- Introduction
- 1 Groups and semigroups: connections and contrasts
- 2 Toward the classification of s-arc transitive graphs
- 3 Non-cancellation group computation for some finitely generated nilpotent groups
- 4 Permutation and quasi-permutation representations of the Chevalley groups
- 5 The shape of solvable groups with odd order
- 6 Embedding in finitely presented lattice-ordered groups: explicit presentations for constructions
- 7 A note on abelian subgroups of p-groups
- 8 On kernel flatness
- 9 On proofs in finitely presented groups
- 10 Computing with 4-Engel groups
- 11 On the size of the commutator subgroup in finite groups
- 12 Groups of infinite matrices
- 13 Triply factorised groups and nearrings
- 14 On the space of cyclic trigonal Riemann surfaces of genus 4
- 15 On simple Kn-groups for n = 5, 6
- 16 Products of Sylow subgroups and the solvable radical
- 17 On commutators in groups
- 18 Inequalities for the Baer invariant of finite groups
- 19 Automorphisms with centralizers of small rank
- 20 2-signalizers and normalizers of Sylow 2-subgroups in finite simple groups
- 21 On properties of abnormal and pronormal subgroups in some infinite groups
- 22 P-localizing group extensions
- 23 On the n-covers of exceptional groups of Lie type
- 24 Positively discriminating groups
- 25 Automorphism groups of some chemical graphs
- 26 On c-normal subgroups of some classes of finite groups
- 27 Fong characters and their fields of values
- 28 Arithmetical properties of finite groups
- 29 On prefrattini subgroups of finite groups: a survey
- 30 Frattini extensions and class field theory
- 31 The nilpotency class of groups with fixed point free automorphisms of prime order
Summary
Introduction
Group theory and semigroup theory have developed in somewhat different directions in the past several decades. While Cayley's theorem enables us to view groups as groups of permutations of some set, the analogous result in semigroup theory represents semigroups as semigroups of functions from a set to itself. Of course both group theory and semigroup theory have developed significantly beyond these early viewpoints, and both subjects are by now integrally woven into the fabric of modern mathematics, with connections and applications across a broad spectrum of areas.
Nevertheless, the early viewpoints of groups as groups of permutations, and semigroups as semigroups of functions, do permeate the modern literature: for example, when groups act on a set or a space, they act by permutations (or isometries, or automorphisms, etc.), whereas semigroup actions are by functions (or endomorphisms, or partial isometries, etc.). Finite dimensional linear representations of groups are representations by invertible matrices, while finite dimensional linear representations of semigroups are representations by arbitrary (not necessarily invertible) matrices. The basic structure theories for groups and semigroups are quite different — one uses the ideal structure of a semigroup to give information about the semigroup for example — and the study of homomorphisms between semigroups is complicated by the fact that a congruence on a semigroup is not in general determined by one congruence class, as is the case for groups.
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- Groups St Andrews 2005 , pp. 357 - 400Publisher: Cambridge University PressPrint publication year: 2007
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