Daniel Lenz: Schreier graphs of Grigorchuk’s group and simple Toeplitz subshifts

Date: 2024-06-13

Time: 16:10 - 17:00

Speaker
Daniel Lenz, Universitaet Jena

Abstract
We consider Laplacians on Schreier graphs arising from Grigorchuk’s group (and more generally certain spinal groups). We show that these are unitarily equivalent to Jacobi operators associated to simple Toeplitz subshifts. We use this to establish Cantor spectrum of Lebesgue measure zero. (Joint work with Rostislav Grigorchuk, Tatiana Nagnibeda and Daniel Sell)