Friday 19 July 2019 |

Events for day: Tuesday 11 September 2018 |

15:00 - 16:00 LectureSteiner 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 ... |