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Events for day: Tuesday 11 September 2018    
           15:00 - 16:00     Lecture
Steiner Triple Systems with High Chromatic Index

School
MATHEMATICS

A Steiner triple system is a set of triples (subsets of ${1,2,dots,n}$) such that every pair is in exactly one triple. A partial parallel class in a Steiner triple system is a subset of its triples that are pairwise disjoint. The chromatic index of a Steiner triple system is the smallest number of partial parallel classes into which its blocks can be partitioned. It has been conjectured that every Steiner triple system of order $v eq 7$ has chromatic index at most $({v+3})/{2}$ when $v equiv3 mod{6}$ and at most $({v+5})/{2}$ when $v equiv 1 mod{6}$. We construct a Steiner triple system of order $v$ with chromatic index at least ...