Polynomials with small norm on compact Riemannian homogeneous manifolds

Abstract

We consider the problem of existence of polynomials with small norm. This range of problems has been extensively studied by many authors in the case of the unit circle (or a compact Abelian group), i.e. when the characters are bounded. In general, on compact homogeneous Riemannian manifolds, the eigenfunctions of the Laplace-Beltrami operator are not uniformly bounded. This creates difficulties of a fundamental nature in applications of known methods and results. The method we develop is based on a geometric inequality between norms induced by two convex bodies in Euclidean space.