Two problems in the theory of finite permutation groups are considered in this thesis:<ul><li> A. transitive groups of degree p, where p = 4q+1 and p,q are prime,</li><li> B. automorphism groups of 2-graphs and some related algebras.</li></ul> Problem A should be seen in the following context: in 1963. N.Ito began a study of insoluble, transitive groups G of degree p on a set Ω, where p = 2q+1 and p,q are prime, showing among other things, that such a group G is 3-transitive. His methods involve the modular character theory of G for both the primes p and q (developed by R.Brauer). He uses this theory to prove facts about the permutation characters of G associated with Ω<sup>(2)</sup> and Ω<sup>{2}</sup>, the sets of ordered and unordered pairs (respectively) of distinct elements of Ω. The first part of this thesis represents an attempt to extend these methods to the case p = 4q+1. The main result obtained is Theorem. Let G be an insoluble, transitive permutation group of degree p, where p = 4q+1 and p.q are prime with p>13. Then G is 3-transitive. Also some progress is made towards a proof that the groups in Problem A are 4-transitive. In the second part of this thesis (Problem B) certain algebras are defined from 2-graphs as follows: let (Ω,Δ) be a 2-graph, that is, Δ is a set of 3-subsets of a finite set Ω such that every 4-subset of Ω contains an even number of elements of Δ. Write Ω= {e<sub>1</sub>....,e<sub>n</sub>}. Given any field F of characteristic 2, make FΩ into an algebra by defining [see text for continuation of abstract].
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:463235 |
| Date | January 1979 |
| Creators | Liebeck, Martin W. |
| Contributors | Neumann, P. M. |
| Publisher | University of Oxford |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://ora.ox.ac.uk/objects/uuid:ea433240-b63c-4896-a780-a608f4ea2b97 |
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