### Cobordism and Topological Field Theories Week 4

#### Posted by Alexander Hoffnung

Welcome to week 4 of the cobordism and TFT seminar at UCR by Chris Carlson. The previous lecture was put up a few weeks ago here. Sorry for the long break, but the next few should be coming in a more timely manner. So keep an eye out. This week’s lecture introduces $2$-dimensional topological quantum field theories and commutative Frobenius algebras.

Here is the new lecture. Thanks to Christopher Walker for preparing these notes and the great pictures. The next lecture will be an introduction to the interactions between quantum field theories and topology by John Huerta.

## Re: Cobordism and Topological Field Theories Week 4

Does the ‘snake lemma’ at the beginning have anything to do with the snake lemma that I know? If so, I don't see it.