Algebraic Combinatorics
Via Finite Group Actions
A. Betten, H. Fripertinger, A. Kerber
August 28, 2001
Actions
Actions of groups
Orbits
Stabilizers
Fixed points
Examples
Cosets
The Cauchy-Frobenius Lemma
The permutation character
The Cauchy-Frobenius Lemma 2
Similar Actions
Exercises
Bilateral classes, symmetry classes of mappings
Double Cosets
Action on k-subsets
Sylows Theorem
Products of Actions
Paradigmatic Examples
Paradigmatic Examples 2
Exercises
Finite symmetric groups
Cycle decomposition
Conjugation
Conjugacy Classes
Generators of the symmetric group
Subgroups of Cyclic Groups
Colourings of the n Gon
The Sign
Splitting Orbits
Rothe diagram and inversions
The Lehmer code and reduced decompositions
Sn as a Coxeter Group
The Exchange Lemma
Exercises
Complete monomial groups
Centralizers of elements in finite symmetric groups
Conjugacy classes in complete monomial groups
Examples
Execises
Enumeration of symmetry classes
Graphs
The cycle type of the induced action on 2-subsets
Some congruences
Exercises
The involution principle
Selfcomplementary graphs
Involutions
The Involution Principle
The Principle of Inclusion and Exclusion
The Garsia-Milne bijection
Exercises
Special symmetry classes
Injective symmetry classes
Surjective symmetry classes
Various combinatorial numbers
Exercises
Weights
Enumeration by weight
Exercises
Cycle indicator polynomials
Exercises
Sums of cycle indicators, recursive methods
A generalization
The Decomposition Theorem
Species
Marks
Constructions
Orbit evaluation
Transversals of symmetry classes
Orbits of centralizers
Recursion and orderly generation
Generating orbit representatives
Symmetry adapted bases
Index
harald.fripertinger@kfunigraz.ac.at,
last changed: August 28, 2001