Just wrapping up my second week at the Banff International Research Station. This week's workshop is on Statistics and Machine Learning. The highlight, for an outsider like me, has definitely been Tselil Schramm's mini-course on the sum-of-squares algorithmic paradigm. A decade's worth of research nicely condensed into four one-hour lectures.

An implementation of the Product Structure Theorem for planar graphs, in Python:


Not exactly industrial-strength, and leans towards simplicity over performance. Still, it can decompose 100k-vertex triangulations in a few seconds. I'm open to feature requests.

Good to see that the pandemic hasn't affected every aspect of our lives. SoDA is still charging exorbitant registration fees:

Banff Alberta, Election Day, 2016, Alan Frieze and Luc Devroye watching election results arrive.

Congratulations to my (now former) student, Luís Fernando Schulz Xavier da Silveira, who successfully defended his PhD thesis titled Turán Triangles, Cell Covers, Road Placement and Train Scheduling on Monday.

This is the first thesis defense I've taken part in where no two participants were in the same room.

Here's an option, Elsevier: Open up your catalogues for the duration of the crisis (at least):

Today the was the first day of three weeks (at least) of home school. This morning was intro to algebra for my nine year-old. Addition, subtraction, and number-recognition for my 5 year old. This afternoon was bicycling and stump-jumping. :)

Rolf explains fragile complexity with a concrete example.

Rant: Commercial publishers suck. Wiley broke my name in a recent article. Even JoCG, which leaves formatting almost entirely up to authors, avoids this.

Luckily, most of the world doesn't have access to the official version so they will see the arXiv version instead.

A few weeks ago, I posted a photo of some happy people who had just proven a theorem a few minutes earlier.

That theorem appears in the arXiv today and the theorem is the title of the paper: Planar Graphs Have Bounded Queue Number.


More important than theorem though, is the tool used to prove it: layered $H$-partitions of small layered width where $H$ has small treewidth.

Expect another result tomorrow: Planar Graphs Have Bounded Nonrepetitive Chromatic Number.


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