Abstract:
In this paper, we establish criterions for the completeness of an exponential system in spaces of functions that are continuous on a convex compact set and holomorphic in the interior of this compact set and in spaces of holomorphic functions in a convex domain in terms of the directional width of a compact set or a domain. The main results are formulated exclusively in terms of the relationship between the breadth in the direction or the diameter of a compact set or a domain, on the one hand, and the so-called logarithmic submeasures or logarithmic block densities of the distribution of exponential system indicators, on the other hand.
Keywords:completeness of systems of functions, exponential system, breadth in the direction, diameter, entire function of exponential type, distribution of roots, support function.