Tag Archives: primitive

A family of non-synchronizing groups

Posted on 06/01/2019 by

As I explained recently, according to the O’Nan–Scott Theorem, a finite primitive permutation group either preserves a Cartesian structure, or is of affine, diagonal or almost simple type. In all these types except the last, the action of the group … Continue reading →

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Imprimitive permutations in primitive groups

Posted on 22/11/2016 by

Asymptotics of permutation counts is a subject with a long history. The result that the proportion of permutations which are derangements (that is, have no fixed points) is very close to 1/e is one of the oldest results in enumerative … Continue reading →

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Regular polytopes, 3

Posted on 07/10/2014 by

In the last two posts on regular polytopes, I gave away something about my method of working. Although I have known about regular polytopes for a long time, I have never attempted to do research on them before. I find … Continue reading →

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