COUNTING G-ORBITS ON THE INDUCED ACTION ON k-SUBSETS

Abstract

Let G be a finite permutation group acting on a finite set Ω. Then we denote by sigmak(G,Ω) the number of G-orbits on the set Ωk, consisting of all k-subsets of Ω. In this thesis we develop methods for calculating the values for sigmak(G,Ω) and produce formulae for the cases that G is a doubly-transitive simple rank one Lie type group. That is G ∼ = PSL(2,q),Sz(q),PSU(3,q) or R(q). We also give reduced functions for the calculation of the number of orbits of these groups when k = 3 and go on to consider the numbers of orbits, when G is a finite abelian group in its regular representation.We then consider orbit lengths and examine groups with "large" G-orbits on subsetsof size 3

Date of Award	1 Aug 2015
Original language	English
Awarding Institution	The University of Manchester
Supervisor	Peter Rowley (Supervisor) & Louise Walker (Supervisor)