# Dor Elimelech (BGU) Restricted permutations and perfect matchings

Abstract:
A restricted permutation of a locally finite directed graph $G=(V,E)$ is a vertex permutation $\pi: V\to V$ for which $(v,\pi(v))\in E$, for any vertex $v\in V$. The set of such permutations, denoted by $\Omega(G)$, with a group action induced from a subset of graph isomorphisms form a topological dynamical system. In the particular case presented by Schmidt and Strasser (2016), where $V=\mathbb{Z}^d$ and $(n,m)\in E$ iff $(n-m)\in A$ ($A\subseteq \mathbb{Z^d}$ is fixed), $\Omega(G)$ is a subshift of finite type.
During the talk we will show a general correspondence between restricted permutations and perfect matchings (also known as dimer coverings). We will use this correspondence in order to compute the topological entropy in a class of cases of restricted $\Z^2$-permutations.

## Date:

Tue, 24/12/2019 - 14:30 to 15:30