John Baez

Workshop on Compositionality, Simons Institute of Computing

December 6, 2016

Compositionality in Network Theory

To describe systems composed of interacting parts, scientists and engineers draw diagrams of networks: flow charts, Petri nets, electrical circuit diagrams, signal-flow graphs, chemical reaction networks, Feynman diagrams and the like. In principle all these different diagrams fit into a common framework: the mathematics of symmetric monoidal categories. This has been known for some time. However, the details are more challenging, and ultimately more rewarding, than this basic insight. Two complementary approaches are presentations of symmetric monoidal categories using generators and relations (which are more algebraic in flavor) and decorated cospan categories (which are more geometrical). In this talk we focus on the latter.

You can see the slides here and a video here:

This talk assumes considerable familiarity with category theory. For a much gentler talk on the same theme, see:

For the other approach to network theory, generators and relations, try this talk:

To read more about the network theory project, go here:

© 2016 John Baez