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# Tag Archives: Seidel

## G2D2, 2: first week

The campus of the China Three Gorges Hotel has a small river, full of waterlilies and lotus flowers. Beside it runs a main road, along which big water trucks run, shooting atomised water from cannon-like structures; we are told this … Continue reading

## Carries, shuffling, and cocycles

Last week we were treated to a lovely lecture by Persi Diaconis. As he so often does, he started with an elementary question: how many carries do you expect if you add n numbers in base b? From there he … Continue reading

Posted in exposition, open problems
Tagged arithmetic, minimal cocycles, riffle shuffles, Seidel, switching
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## The Graph Extension Theorem

I made some notes on the Graph Extension Theorem for a new research project. They may be of wider interest, so here is a summary. Shult’s Graph Extension Theorem is a simple device for showing that certain permutation groups have … Continue reading

Posted in exposition
Tagged Higman, Seidel, Shult, switching, transitive extension, two-graph
4 Comments