Growth of masses of crystalline measures

Abstract

Let $\mu$ be a measure on the Euclidean space $\R^d$ of unbounded total variation that is positive or translation bounded and has a pure point Fourier transform in the sense of distributions $\hat\mu$. We prove that the measure $\nu$ with the same support as $\hat\mu$ and masses equal to the squares of the masses of $\hat\mu$ is translation bounded. We also prove that if $\mu$ is as above and the restriction of its spectrum, i.e., of the support of $\hat\mu$, to each ball of fixed radius is a linearly independent set over $\Z$, then the measure $\hat\mu$ is also translation bounded. These results imply certain conditions for a crystalline measure to be a Fourier quasicrystal.