I want to go back over something from Part 11, but in a more systematic way that I hope is easier to follow. I’m stating these facts roughly now, to not get bogged down. But I’ll state them precisely, ...

I’ve been blogging a bit about medieval math, physics and astronomy over on Azimuth. I’ve been writing about medieval attempts to improve Aristotle’s theory that velocity is proportional to force, ...

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 ...

May 15, 2010 In “week298” of This Week’s Finds, learn about finite subgroups of the unit quaternions, finite subloops of the unit octonions, Lie n-superalgebras built using division algebras, and Duff ...

The Eighth International Conference on Applied Category Theory ( https://easychair.org/cfp/ACT2025) will take place at the University of Florida on June 2-6, 2025. The conference will be preceded by ...

for all infinite sets X X and Y Y. Proving this required most of the concepts and results from the second half of the course: well ordered sets, the Cantor–Bernstein theorem, the Hartogs theorem, Zorn ...

Dec 15, 2024 More detail on the Cycle Length Lemma, a basic result in the theory of random permutations. We prove a categorified version of this result, which is an equivalence of groupoids, and then ...

This is the homepage for the UT Geometry and Quantum Field Theory Seminar. At the organizational meeting we will flesh out the details of our plans for the semester. Below are some suggestions to get ...

Nov 22, 2024 The final chapter of this course on secretly-categorical set theory. Axiomatic Set Theory 9: The Axiom of Choice Nov 15, 2024 The penultimate week of this axiomatic set theory course, ...

Previously: Part 8. Next: Part 10. 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. The section I most enjoyed ...

Hello [email protected]. So nice of you to stop by. I'm a member of the Theory Group here at UT. I've been at UT since September 1994. Before coming here, I was an Assistant Professor in the theory ...