## October 14, 2018

### Topoi of G-sets

#### Posted by John Baez

I’m thinking about finite groups these days, from a Klein geometry perspective where we think of a group $G$ as a source of $G$-sets. Since the category of $G$-sets is a topos, this lets us translate concepts, facts and questions about groups into concepts, facts and questions about topoi. I’m not at all good at this, so here are a bunch of basic questions.

Posted at 5:36 PM UTC | Permalink | Followups (52)

## October 3, 2018

### Category Theory 2019

#### Posted by Tom Leinster

The major annual category theory conference will be held in Edinburgh next year:

Category Theory 2019

University of Edinburgh

7-13 July 2019

Organizing committee: Steve Awodey, Richard Garner, Chris Heunen, Tom Leinster, Christina Vasilakopoulou.

As John has just pointed out, this is followed two days later by the Applied Category Theory conference and school in Oxford, very conveniently for anyone wishing to go to both.

Posted at 11:27 PM UTC | Permalink | Followups (2)

## October 2, 2018

### Applied Category Theory 2019

#### Posted by John Baez

I’m helping organize ACT 2019, an applied category theory conference and school at Oxford, July 15-26, 2019. Here’s a ‘pre-announcement’.

More details will come later, but here’s some good news: it’s right after the big annual worldwide category theory conference, which is in Edinburgh in 2019. So, conference-hopping category theorists can attend both!

Posted at 5:00 PM UTC | Permalink | Followups (6)