Speaker
Prof.
Alexander Ivanov
(Imperial College London)
Description
Let $\Gamma$ be a finite cubic graph, let $G$ be an edge-transitive automorphism group of $\Gamma$, let $\{x,y\}$ be an edge of $\Gamma$, and let ${\cal A}=\{G(x),G(y)\}$ be the amalgam formed by the corresponding vertex stabilizers. In a groundbreaking paper of 1980 D.M.Goldschmidt proved that $|G(x)|=|G(y)|$ divides $2^7 \cdot 3$ and that there are exactly fifteen possibilities for the isomorphism type of ${\cal A}$. I am planning to discuss the structure of the Godlschmidt amalgams with a particular emphasis on the largest one, embedded into the automorphism group ${\rm Aut}\,(M_{12})$ of the sporadic Mathieu group $M_{12}$.
Primary author
Prof.
Alexander Ivanov
(Imperial College London)
