Tag Archives: tournaments

Two combinatorics colloquia

One of the rituals of Spring for combinatorialists in the UK is meeting in London in May for two one-day colloquia, one at Queen Mary and the other at LSE. As always, this year’s colloquia provided very good instruction and … Continue reading

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Generating singular maps

Last week, Max Gadouleau and Alonso Castillo-Ramirez visited St Andrews. With James Mitchell, we worked on a problem about generating the semigroup of singular maps on a set (the full transformation semigroup minus the symmetric group). As usual in this … Continue reading

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Easy to state, hard to solve?

I described here how Pablo Spiga and I showed that all but finitely many nontrivial switching classes of graphs with primitive automorphism group contain a graph with trivial automorphism group, and found the six exceptions. (The trivial switching classes are … Continue reading

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