Category Archives: exposition

a post aimed to teach something

The end of the conference

The last day of the conference was over. Here are a couple of closing remarks. We have certainly heard an amazing collection of talks over the last week! I didn’t yet mention the other short course, given by Simeon Ball … Continue reading

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Green on derangements

I have to mention Ben Green again. Yesterday he gave a lovely colloquium talk on a problem I had cracked my head against some years ago without much success. As usual with derangements, the story begins with a classical result: … Continue reading

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More graphs

John Bamberg is reporting on New Directions in Combinatorics on SymOmega (his report on Day 1 is here), so I will not even attempt to be comprehensive, but will just pick some plums. Not very long ago, I reported the … Continue reading

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London Combinatorics Colloquia 2016

The tenth London Combinatorics Colloquia took place over the last two days. (As was pointed out, this is not the same as the tenth anniversary!) A dozen really excellent talks, and I cannot do justice to them all, so I … Continue reading

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Guessing numbers of graphs

A paper, “Guessing games on triangle-free graphs”, by Anh Dang, Søren Riis, and me, has just appeared in the Electronic Journal of Combinatorics. Here is a brief discussion of what it is about. It is always a pleasant surprise when … Continue reading

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The power graph yet again

Five years ago, I posted a short update on the power graph of a group. Now, finally, the paper resulting from this has appeared on the arXiv; my coauthors are Ghodratollah Aalipour, Saieed Akbari, Reza Nikandish and Farzad Shaveisi. I … Continue reading

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Partition homogeneity

This post discusses a paper by Jorge André, João Araújo and me, which has just been accepted for the Journal of Algebra. There is a slight tangle to the history of this paper, which I want to describe. First a … Continue reading

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