ペーパー @paper3510mm@mathtod.online

They just don't stop! Besides their Joy of Abstraction book club, the Topos Institute also has *another* way for you to start learning category theory.

It's called the CT Outreach Panel, and it's happening on March 16, 17:00 UTC.

Some of the best explainers of category theory in the world - Emily Riehl, Eugenia Cheng, Tai-Danae Bradley, Paul Dancstep and Oliver Lugg - will explain their approaches to the subject and answer questions.

You can submit questions here:

https://topos.site/ct-outreach-self-learners/

This post by @johncarlosbaez about rig categories is great!
https://mathstodon.xyz/@johncarlosbaez/109801982980939381

It got me thinking about my favorite example that's not exactly FinSet. It's a rig category Z whose objects are integers. Its only morphisms are automorphisms, and each automorphism group is ℤ/2 = {±1}. Even though addition of integers is commutative, the symmetry isomorphism in Z is nontrivial! The symmetry isomorphism
β: m + n ≅ n + m
is the element (-1)ᵐⁿ in Z(m+n,m+n).

(1/5)

finally found a journal for my expository paper on (co)simplicial (co)presheaves! first solo publication to actually appear (one of my thesis ones was accepted a couple of months ago but seems to be stuck in academic publication limbo)

https://cm.episciences.org/10359

Imagine mentioning "symplectic meanders associated to seaweed" to someone, and imagine them believing it is not part of an elaborate joke. This cannot be done.

mathlogに投稿しました

圏論に元を取り戻そう
https://mathlog.info/articles/2557

高評価、コメント、待ってます