Aperiodic order, integrated density of states and the continuous algebras of John von Neumann

Abstract

Lenz and Stollmann recently proved the existence of the integrated density of states in the sense of uniform convergence of the distributions for certain operators with aperiodic order. The goal of this paper is to establish a relation between aperiodic order, uniform spectral convergence and the continuous algebras invented by John von Neumann. We illustrate the technique by proving the uniform spectral convergence for random Schodinger operators on lattices with finite site probabilities, percolation Hamiltonians and for the pattern-invariant operators of self-similar graphs.