## May 22, 2013

### Philosophy Talks in Oxford

#### Posted by Simon Willerton

Guest post by Bruce Bartlett

On Monday, David Corfield and Kobi Kremnitzer gave philosophy talks in a snazzy new building at Oxford:

The talks shared homotopy type theory as a common theme. The name “Per Martin-Löf” was mentioned a lot, which was good for me since I had always thought Martin and Löf were two separate people:

Notes are available above, but I will try to give some brief impressions.

Posted at 5:26 PM UTC | Permalink | Followups (15)

### In the News

#### Posted by David Corfield

Applications of category theory are described by Julie Rehmeyer in ScienceNews under the banner

One of the most abstract fields in math finds application in the ‘real’ world.

Now, how about applications in the real world?

Posted at 9:17 AM UTC | Permalink | Followups (4)

## May 17, 2013

### Semantics of Proofs in Paris

#### Posted by John Baez

There’s going to be a “thematic trimester” in Paris starting next spring:

If you like applications of category theory to logic and computer science, there should be a lot for you here!

Posted at 10:15 PM UTC | Permalink | Followups (1)

## May 16, 2013

### The Propositional Fracture Theorem

#### Posted by Mike Shulman

Suppose $X$ is a topological space and $U\subseteq X$ is an open subset, with closed complement $K = X\setminus U$. Then $U$ and $K$ are, of course, topological spaces in their own right, and we have $X = U\sqcup K$ as a set. What additional information beyond the topologies of $U$ and $K$ is necessary to enable us to recover the topology of $X$ on their disjoint union?

Posted at 7:47 PM UTC | Permalink | Followups (3)

## May 14, 2013

### Bounded Gaps Between Primes

#### Posted by Tom Leinster

Guest post by Emily Riehl

Whether we grow up to become category theorists or applied mathematicians, one thing that I suspect unites us all is that we were once enchanted by prime numbers. It comes as no surprise then that a seminar given yesterday afternoon at Harvard by Yitang Zhang of the University of New Hampshire reporting on his new paper “Bounded gaps between primes” attracted a diverse audience. I don’t believe the paper is publicly available yet, but word on the street is that the referees at the Annals say it all checks out.

What follows is a summary of his presentation. Any errors should be ascribed to the ignorance of the transcriber (a category theorist, not an analytic number theorist) rather than to the author or his talk, which was lovely.

Posted at 8:44 PM UTC | Permalink | Followups (41)