Previously: Part 8. It’s the penultimate week of the course, and up until now we’ve abstained from using the axiom of choice. But this week we gorged on it.

Gerard Westendorp has a real knack for geometry, and here is his answer. Here is Thurston’s procedure. First draw the lattice of Eisenstein integers in the complex plane: ...

TrackBack URL for this Entry: https://golem.ph.utexas.edu/cgi-bin/MT-3.0/dxy-tb.fcgi/3578 ...

You can now apply for the 2025 Summer Research Associate program at the Topos Institute! This is a really good opportunity. Details and instructions on how to apply are in the official announcement. A ...

Earlier this month the Mathematics Institute at Uppsala University hosted a conference called Categorification in Algebra and Topology, clearly a theme close to our collective heart. As yet there are ...

Nov 11, 2024 20:33 Going back and rereading Tom’s old post, what Tom wrote about there amounted to working with a finite parameter set ...

Sep 18, 2018 Tai-Danae Bradley has a new booklet on applied category theory.

May 31, 2011 The relationships between Euler characteristic and different kinds of Möbius inversion. This Week’s Finds in Mathematical Physics (Week 295) Apr 17, 2010 In “week295” of This Week’s Finds ...

Oct 9, 2007 On weak Lie n-algebras, differential graded Clifford algebra and Roytenberg’s work on weak Lie 2-algebras.

Nov 7, 2024 00:45 Here’s a way to argue that Gerard’s solution to my puzzle is correct. Thurston showed that any star of the ...