Convex bodies with a point of curvature do not have Fourier bases
arXiv:math/9911167
Abstract
We prove that no smooth symmetric convex body with at least one point of non-vanishing Gaussian curvature can admit an orthogonal basis of exponentials. (The non-symmetric case was proven by Kolountzakis). This is further evidence of Fuglede's conjecture, which states that such a basis is possible if and only if can tile by translations.
5 pages, no figures, submitted to Amer. J. Math