• Linkage

    • Michael Mitzenmacher is making an unusual request for publicity for his NON-participation in a conference (\(\mathbb{M}\)). It calls itself ICAIM, the International Conference on Artificial Intelligence and Mathematics, to be held in Nanjing in September, and it falsely lists Mitzenmacher as a conference chair, Mike Goodrich as program chair, and Jelani Nelson as a program committee member, among others. None of Michael, Mike, and Jelani have agreed to allow their names to be used in this way. The conference contact email goes to a known spam/phishing site. It appears to be a scam. Be aware!
  • Mendocino, sakura, and my father

    Last weekend I made a quick visit to my mother in Mendocino for a memorial service for my father, Tony Eppstein. He died last August, I think while I was on a plane to Tokyo, but I had seen him only days before and it was expected.

  • Pre-April-fools linkage

    As always, you can see these earlier and more spread out by following my Mastodon account. These linkage posts are just a redundant copy of what I post and boost there to make it easier for later me (and maybe others) to find the same content without having to scroll through miles of other posts to reach it. The “\(\mathbb{M}\)” links go to the Mastodon posts, where there may be more discussion.

  • One-face torus

    In the graduate version of my just-concluded graph algorithms course, one of the exam questions asked the students to find the faces of a topological embedding of the complete bipartite graph \(K_{2,3}\) (the embedding in which the two degree-three vertices have the same clockwise order of neighbors as each other), compute its Euler characteristic, and determine from the result whether the embedding is planar. Some of the students found it confusing (it was intended to be the hardest problem on the exam) so I thought I’d post an answer here.

  • Triforce toroids

    Recent edits to the Wikipedia article on toroidal polyhedra led me to a 1997 geometry.research discussion thread, “Polyhedra of positive genus”, in which John Conway describes a toroidal polyhedron with 36 equilateral-triangle sides, and suggests that this might be the fewest sides possible for a toroidal deltahedron.

  • Linkage for mid-March

    • Robin Houston wonders about cuboid terminology. The specific question is whether it should mean a shape with six rectangular sides (as commonly taught in school) or a shape with six quadrilateral sides (as used in some research communities). Let’s not even speak about Branko Grünbaum’s use of it to mean a shape formed by gluing together a power-of-two number of six-quad-side shapes.
  • Spanners that don't change much

    I have another preprint on the arXiv today with my student Hadi Khodabandeh: “Maintaining light spanners via minimal updates”, arXiv:2403.03290.

  • Linkage for leap day

  • Linkage

  • Linkage

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