Author Archives: Peter Cameron

About Peter Cameron

I count all the things that need to be counted.

A request

In 1956, Helmut Wielandt proved that a primitive permutation group whose degree is twice a prime p is doubly transitive, unless p has the form 2a2+2a+1, in which case the group has rank 3, and its subdegrees are a(2a+1) and … Continue reading

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I’d like to see this solved

Here is a problem that I would really like to see solved. I have spent quite a bit of time on it myself, and have suggested it to a few other people, but it still resists all attacks, though it … Continue reading

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A problelm

Given a finite permutation group G on a set X, the permutation character π of G is the function on G mapping an element g to its number of fixed points in X. This is a character of G, the … Continue reading

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Some things get better

Amid the gloom, we went for a short walk in Dura Den, one of the most scenic parts of Fife. At the end of the den is the village of Pitscottie, with the White Chimneys café. To our pleasure and … Continue reading

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St Andrews Combinatorics Day

We are having a home-grown combinatorics day in St Andrews next Tuesday, 24 May. Here is the programme. Come along if you are nearby on the day. It will be in Lecture Theatre B in the Mathematical Institute. 11-11:30 Rosemary … Continue reading

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John McKay

I learned only yesterday that John McKay died a month ago. John McKay made the kind of contribution to the subject that most mathematicians can only dream of, in part because of his wide-ranging interests and keen observation. He was … Continue reading

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Peter Neumann’s 3p paper

In 1955, Helmut Wielandt published a paper proving the following theorem: Let G be a primitive permutation group of degree 2p, where p is a prime greater than 3, which is not doubly transitive. Then p = 2a2+2a+1 for some positive integer … Continue reading

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Peter Neumann memorial meeting

On Saturday, I was in Oxford for a memorial meeting for Peter Neumann, organised by Chris Hollings for the British Society for the History of Mathematics (of which Peter was a past president). It was a hybrid meeting, with half … Continue reading

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Taylor series

Today, XKCD, with tongue in cheek, is saying that “The Taylor series should have been canceled after the first term”. After a flying visit to London (more about that shortly), I am reminded again that at least the second term … Continue reading

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An O’Nan-Scott note

My old friend Leonard Soicher is visiting St Andrews this week, having made a better job of retiring than I did. Today he gently took me to task for using the expression “simple diagonal type” for one of the types … Continue reading

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