### Rigidity and Cutting and Stacking Constructions

- Series
- CDSNS Colloquium
- Time
- Wednesday, December 6, 2017 - 11:15 for 1 hour (actually 50 minutes)
- Location
- Skiles 249
- Speaker
- Kelly Yancey – Institute for Defense Analyses – kyancey@math.umd.edu

A special class of dynamical systems that we will focus on are substitutions. This class of systems provides a variety of ergodic theoretic behavior and is connected to self-similar interval exchange transformations. During this talk we will explore rigidity sequences for these systems. A sequence $\left( n_m \right)$ is a rigidity sequence for the dynamical system $(X,T,\mu)$ if $\mu(T^{n_m}A\cap A)\rightarrow \mu(A)$ for all positive measure sets $A$. We will discuss the structure of rigidity sequences for substitutions that are rank-one and substitutions that have constant length. This is joint work with Jon Fickenscher.