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Tutte seminar - Peter NelsonExport this event to calendar

Friday, June 6, 2014 — 3:30 PM EDT

Dense Triangle-free Binary Matroids

Speaker: Peter Nelson
Affiliation: University of Waterloo
Room: Mathematics 3 (M3) 3103

Abstract:

Brandt and Thomassé proved that a triangle-free graph $G$ with minimum degree greater than $\frac{1}{3}|V(G)|$ has chromatic number at most 4. On the other hand, Hajnal proved that for all real $\alpha > 0$ there exist triangle-free graphs G with minimum degree at least $(\frac{1}{3} - \alpha)|V(G)|$ and arbitrarily large chromatic number. I discuss a surprisingly similar theorem for triangle-free binary matroids, where we consider their 'critical number' in place of chromatic number. This is joint work with Jim Geelen. No knowledge of matroid theory will be assumed.

Location 
M3 - Mathematics 3
3103
200 University Avenue West

Waterloo, ON N2L 3G1
Canada

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