“…The aim of this paper is first to recall the part of this program specifically devoted to the notions of sets of beta-integers ( Z β ), when β is a quadratic Pisot-Vijayaraghavan number, and associated beta-lattices (or β-lattices), and next to present some original results concerning the Fourier properties and diffraction spectra of Delone sets on beta-integers and on beta-lattices, and more generally of weighted Dirac combs supported by beta-lattices. This approach makes prominent the role played by nonclassical numerations [16] [26], associated with substitutive dynamical systems [34], and amounts to replace the traditional set of rational integers Z by Z β . This allows computations over this new set of numbers, where lattices are replaced by beta-lattices.…”