SEMINAR:
Groups and Combinatorics Seminar, Graphs and transitivity on 2-geodesics
Fri, 17 Jan 2014 15:00 - Blakers Lecture Theatre G.18
Alice Devillers (UWA)
Alice Devillers (UWA)
will speak on
Graphs and transitivity on 2-geodesics
at 3pm Friday January the 17th in Blakers Lecture Theatre.
Abstract :
Joint work with Wei Jin, Cai Heng Li, Cheryl Praeger, Akos Seress.
An s-geodesic in a graph is a shortest path connecting two vertices at
distance s. We say that a graph is locally transitive on s-geodsics if
the stabiliser of any vertex is transitive on the s-geodesics starting
at that vertex. Being locally transitive on s-geodesic is not a monotone
property: if an automorphism group G of a graph is locally transitive
on s-geodesics, it does not follow that G is locally transitive on
shorter geodesics. For instance, (local) transitivity on 2-geodesics
does not imply local transitivity on arcs (1-geodesics).
In this talk, I will first show a nice characterisation of all graphs
that are locally transitive on 2-geodesics, but not locally transitive
on 1-geodesics.
Then I will describe graphs that are (locally) transitive on 2-geodesics
and on arcs, in terms of their local structure.
For more information:
Irene Pivotto
irene.pivotto@uwa.edu.au
Starts : Fri, 17 Jan 2014 15:00
Ends : Fri, 17 Jan 2014 16:00
Last Updated : Tue, 21 Jan 2014 13:31