G2D2, 1: setting the scene

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

1. G2C2: Groups and graphs, cycles and coverings, Novosibirsk, Russia
2. G2A2: Groups and graphs, algorithms and automata, Ekaterinburg, Russia
3. G2S2: Groups and graphs, spectra and symmetries, Novosibirsk, Russia
4. G2M2: Groups and graphs, metrics and manifolds, Ekaterinburg, Russia
5. G2R2: Groups and graphs, representations and relations, Novosibirsk, Russia

The event following this one will be G2G2: Groups and graphs, geometries and GAP, and will be in Rogla and Portorož, Slovenia, as a satellite meeting of the European Congress of Mathematics.

This sequence inevitably invites one to play alphabet games. I would like to say “Groups and graphs, symmetry and structure”, but we have already had G2S2 which included symmetries. So perhaps I will say “G2I2: Groups and graphs, incidence and independence”. Perhaps “G2F2: Groups and Graphs, fields and functions” (or F2 could be the field with two elements).

The meetings are instructional workshops as well as conferences, and Rosemary and I are doing our double act on “Laplacian eigenvalues and optimality”, indeed we start off the meeting at 9am tomorrow morning.

Last week we were in the beautiful town of Hangzhou on West Lake, with its lotus blossoms at the peak of perfection, willow trees overhanging the water on which small boats plied, and pagodas standing above the trees.

I gave a short course on “Four precious jewels”: you can find the slides on my St Andrews web page. (I have talked about this before but the short course gave the opportunity for a slightly longer presentation.) Yesterday we took the train from Hangzhou to Yichang, a seven-hour journey.

Things were in some doubt, as Hangzhou was battered by Typhoon Lekina, which brought heavy rain and strong winds over the previous two days; but the morning dawned fine and clear with hardly a breeze, and everything worked fine.

I hope to report on the meeting later, firewalls and slowness of response permitting.