Graphs with lots of symmetry - a local perspective

55 mins 17 secs,  426.03 MB,  WebM  640x360,  29.97 fps,  44100 Hz,  1.02 Mbits/sec
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Description: Morgan, L
Tuesday 11th February 2020 - 16:00 to 17:00
 
Created: 2020-02-12 14:56
Collection: Groups, representations and applications: new perspectives
Publisher: Isaac Newton Institute
Copyright: Morgan, L
Language: eng (English)
Distribution: World     (downloadable)
Explicit content: No
Aspect Ratio: 16:9
Screencast: No
Bumper: UCS Default
Trailer: UCS Default
 
Abstract: In this talk we will focus on groups acting on graphs with a good amount of symmetry, such as vertex transitivity. Several conjectures have connected global and local properties of the graphs in this class. In particular, “global" can refer to the number of automorphisms of a graph, and local then refers to certain conditions placed on the local action, that is, the action induced by a vertex-stabiliser on the neighbours of the vertex it fixes. A conjecture of Weiss from 1978 asserts that under mild conditions on this local action the number of automorphisms of a connected vertex-transitive graph should be bounded by a function of the valency. This conjecture is still very much open. I will report on recent progress on an expanded version of the conjecture which uses tools from group theory developed for the classification of the finite simple groups.
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