Tag Archives: groups

Graphs on groups, 3

Posted on 07/02/2021 by Peter Cameron

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 →

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G2D2, 1: setting the scene

Posted on 12/08/2019 by Peter Cameron

I’m in Yichang, at the China Three Gorges University, for the conference and summer school G2D2 (“Groups and graphs, designs and dynamics”). This is the sixth meeting in the series: the previous ones were G2C2: Groups and graphs, cycles and … Continue reading →

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Normal

Posted on 14/11/2018 by Peter Cameron

There are various overused terms in mathematics. “Normal” is one of them. Perhaps the four commonest uses are the following: A complex square matrix is normal if it commutes with its conjugate transpose. Normal matrices are precisely the ones which … Continue reading →

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BCC, day 2

Posted on 07/07/2015 by Peter Cameron

There was a London Mathematical Society regional meeting in the University of Warwick today, to be followed by a workshop on finite simple groups to celebrate the birthday of Richard Lyons, one of the pioneers and heroes of the Classification. … Continue reading →

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OuLiPo

Posted on 08/01/2015 by Peter Cameron

OuLiPo, or Ouvroir de Littérature Potentielle (which they translate as “Charity bazaar of potential literature”) were a collection of writers I knew little about until yesterday. I knew a couple of things: Martin Gardner wrote about them, mentioning among other … Continue reading →

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Entropy and groups

Posted on 27/02/2014 by Peter Cameron

Yesterday I gave a talk on a theorem of Terence Chan, which he spoke about at a network coding meeting at Queen Mary in late 2012. He sketched a proof on the common room table after the talk, and I … Continue reading →

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Lecture notes

Posted on 28/11/2013 by Peter Cameron

I have decided to follow Dima’s suggestion and post my collection of lecture notes here. You will find them from the page “Lecture notes” on the menu bar at the bottom of the picture at the top of the blog. … Continue reading →

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Transitivity and synchronization

Posted on 15/07/2011 by Peter Cameron

Let Sn be the symmetric group of all permutations of {1,…,n}, and Tn the full transformation monoid of all functions from this set to itself. Recently I have come to the meta-conjecture that there is a fairly close analogy between … Continue reading →

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Groups with unique involution

Posted on 22/06/2011 by Peter Cameron

I discussed the binary polyhedral groups in the second post on the ADE diagrams. A more general class of groups has cropped up a couple of times recently, namely finite groups containing a unique involution. I’d like to discuss them … Continue reading →

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