## July 30, 2023

### ACT 2023 — Network Theory Talks

#### Posted by John Baez

It’s not too late to register to join talks on Zoom at Applied Category Theory 2023. It starts on Monday July 31, 2023! But if you miss out, you should be able to watch everything later on YouTube.

Here’s where you can register:

https://www.eventbrite.com/e/applied-category-theory-2023-registration-643212404617

and here’s the program of talks:

https://act2023.github.io/programme.html

Besides talks there will also be tutorials:

Monday (simultaneously):

David Jaz Myers, Lenses

Paolo Perrone, Markov categories

Tuesday (simultaneously):

Dorette Pronk, Double categories

Evan Patterson and Owen Lynch, AlgebraicJulia

The conference is big, so let me just point out a few talks connected to network theory.

## July 9, 2023

### Who Invented Monoidal Categories?

#### Posted by John Baez

Most people would say Mac Lane invented monoidal categories. But the history is more complicated — as usual.

## July 8, 2023

### Profinite Group Actions

#### Posted by John Baez

I have three questions. I have some guesses about the answers, so don’t think I’m completely clueless. But I’m clueless enough that I’d prefer to just give the questions, not my guesses.

## July 6, 2023

### Agent-Based Models (Part 1)

#### Posted by John Baez

I’m working with Nate Osgood and other folks to develop better modeling tools for epidemiologists. Right now we’re trying to develop a category-based framework for agent-based models. It’s a bit tough since many different techniques are used in such models, without yet an overarching discipline — Nate likened it to the ‘wild West’. I have a lot to learn, but I thought I should start keeping notes on our conversations.

I may or may not post future installments here: I mainly talk about applied category theory on the Azimuth blog. But I thought some of you here might like to know this is going on.

So, what’s the deal with agent-based models?