Thu 9 November 2017, 16:30–18:45
ERATO MMSD Takebashi Site Common Room 3
http://group-mmm.org/eratommsd/access.html
16:30-17:30
Jurriaan Rot (Radboud University),
Traces and Triangles
In the theory of coalgebras, trace semantics can be defined in various distinct ways, including through algebraic logics, the Kleisli category of a monad or its Eilenberg-Moore category. I will talk about recent joint work with Bart Jacobs, which elaborates two new unifying ideas in the theory of coalgebraic trace semantics: 1) previous approaches can be placed and connected in so-called state-and-effect triangles, that arise in the semantics of programs; 2) coalgebraic trace semantics is naturally presented in terms of corecursive algebras. This perspective puts the different approaches under a common roof, and allows us to derive conditions under which they coincide.
17:45-18:45
Kenta Cho (Radboud University),
String diagrams in probability theory
String diagrams are a graphical language for monoidal categories, which has become very popular in categorical quantum mechanics initiated by Abramsky and Coecke. In this talk I will explain that string diagrams are also useful for (classical) probability theory. The Kleisli categories of the distribution and the Giry monad give concrete interpretation of string diagrams, respectively, for discrete probability and general measure-theoretic probability. Topics include disintegration, Bayesian inversion, and conditional independence. The talk is based on joint work with Bart Jacobs; see preprint https://arxiv.org/abs/1709.00322.