On the spectra of Pisot-cyclotomic numbers

Abstract

We investigate the complex spectra \[ X^{\mathcal A}(\beta)=\left\{\sum_{j=0}^na_j\beta^j : n\in{\mathbb N},\ a_j\in{\mathcal A}\right\} \] where $\beta$ is a quadratic or cubic Pisot-cyclotomic number and the alphabet $\mathcal A$ is given by $0$ along with a finite collection of roots of unity. Such spectra are discrete aperiodic structures with crystallographically forbidden symmetries. We discuss in general terms under which conditions they possess the Delone property required for point sets modeling quasicrystals. We study the corresponding Voronoi tilings and we relate these structures to quasilattices arising from the cut and project method.