Thursday, February 13, 2020 1:00 pm
-
1:00 pm
EST (GMT -05:00)
Title: Moore Graphs
| Speaker: | Chris Godsil |
| Affiliation: | University of Waterloo |
| Room: | MC 5417 |
Abstract:
Moore graphs were introduced by Hoffman and Singleton in a fundamental paper. They can be defined as graphs with diameter $d$ and girth $2d+1$. Hoffman and Singleton proved that there are at most four Moore graphs of diameter two. It was shown later (by Damerell and by Bannai and Ito) that the only Moore graphs of diameter greater than two are the cycles. (Hoffman once lamented to me that is was a pity that there were so few Moore graphs.)
I
will
discuss
the
basic
theory
of
Moore
graphs
and
present
a
summary
of
Damerell's
proof.