As a digression from our usual fare on the n n -Café, here’s one of my favorites, about an early theory of the Solar System, ...

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 ...

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 ...

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 ...

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 1, 2022 John Baez is giving a talk on categories and epidemiology on Wednesday November 2nd, viewale online at noon UTC. A Categorical Understanding of the Proof of Cantor-Schröder-Bernstein? Dec ...