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# Author Archives: Peter Cameron

## Hoffman, Lovász and Haemers

At the weekend I attended remotely a memorial session for Alan Hoffman, organised by Bill Pulleyblank. I found it informative, as well as moving. Hoffman is well-known in the algebraic graph theory community for a number of remarkable achievements, including … Continue reading

Posted in events
Tagged Alan Hoffman, algebraic graph theory, eigenvalues, Laszlo Lovasz, optimization, WIllem Haemers
1 Comment

## Three passages

[Dmitri] Egorov [founder of the Moscow School of Mathematics] was a very reserved and modest man, so much so that it would be easy to believe that he lived only for mathematics. […] His publications do not reveal any evidence … Continue reading

Posted in Uncategorized
5 Comments

## Graphs on groups, 4

Here is a small problem, mixing group theory and number theory, which might appeal to someone. A couple of definitions. The power graph of a group G has an edge from x to y if one is a power of … Continue reading

## Graphs on groups, 3

Since this stuff keeps growing, I have decided to keep the most recent version on the web. It is now nearly twice as long as the first version I circulated. If you are interested, please take a copy: it’s at … Continue reading

## 13th Iranian International Group Theory Conference

This week has been rather a rush. As well as the first week of semester (and my first ever experience of on-line undergraduate lecturing), I have been attending the 13th Iranian International Group Theory Conference in Urmia, Iran. (I had … Continue reading

Posted in events
Tagged Bernhard Neumann, Carlo Casolo, Eugenio Gianelli, Gareth Jones, Sasha Ivanov, Urmia
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## Graphs on groups, 2

I wrote the long post about this to try to write it out of my system. No luck … I mentioned in that survey that every finite graph is embeddable as induced subgraph in the enhanced power graph, deep commuting … Continue reading

Posted in doing mathematics, mathematics
Tagged commuting graph, enhanced power graph
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## Cheryl Praeger

Good news for a change. I just heard that Cheryl (my mathematical sister, third most prolific coauthor, and good friend) has been made a Companion of the Order of Australia. https://www.abc.net.au/news/2021-01-26/professor-cheryl-praeger-receives-companion-order-of-australia/13089958 Congratulations Cheryl!

## Alan Hoffman

I have just heard the news that Alan Hoffman has died, at the age of 96. There is much to say about Alan; I will restrict myself to my own person perspective, and not even all of that; I didn’t … Continue reading

## Family

The coincidence of Peter Neumann’s funeral and Eric Lander’s elevation in the last few days has inevitably made me think about family (in the mathematical sense). First, pictures of my aunts and uncles, brothers and sisters, sons and daughters, taken … Continue reading