1. Department of Mathematics, Bar-Ilan University, USA 2. Department of Mathematics, University of Maryland, Institute for Systems Research, USA 3. Department of Mathematics, Wichita State University, Wichita, Kansas
Abstract:
The paper is devoted to the following problem. Consider the set of all radial functions with centers at the points of a closed surface inRn. Are such functions complete in the spaceLq(Rn)? It is shown that the answer is positive if and only ifq is not less than 2n/(n + 1). A similar question is also answered for Riemannian symmetric spaces of rank 1. Relations of this problem with the wave and heat equations are also discussed.