Author Archives: Peter Cameron

About Peter Cameron

I count all the things that need to be counted.


To return to an old theme: Today my h-index has reached 50, at least in the opinion of Google Scholar. According to this site, I have 10259 citations. In case you think this is unreasonably high, you might turn to … Continue reading

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Lunardi’s landing place

The first flight in Scotland was made by the Italian balloonist Vincenzo Lunardi, on 5 October 1785. Early balloonists had no control over their vehicles, and on this occasion the wind took him from Edinburgh, over the Firth of Forth, … Continue reading

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Road closures and idempotent-generated semigroups

The University of St Andrews is installing a biomass boiler, to provide hot water to heat University buildings, on the old paper mill site at Guardbridge. The water has to be piped four miles to St Andrews, and this big … Continue reading

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A crash course on group theory

I have just finished a crash course on group theory at Universidade de Lisboa. The notes are here. From the preface: On a visit to Universidade de Lisboa in November 2016, I was asked to give a “crash course” in … Continue reading

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Michel Deza

I have just heard that Michel Deza died in an accidental fire in his apartment in Paris. Michel was one of my earliest collaborators, and a good friend. This is not an obituary, just a few words to mark his … Continue reading

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Rainbows in the plane

As usual in Lisbon, I have been working with João Araújo on semigroups. But sometimes research has unusual spin-offs, such as the following curious fact: Fact If the points of a projective plane are coloured with four colours (all of … Continue reading

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Imprimitive permutations in primitive groups

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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