Laguerre Entire Functions and Related Locally Convex Spaces
  A scale of the Frechet spaces of exponential type entire functions of one complex variable is considered. Certain special properties of subsets of these spaces consisting of Laguerre entire functions, which are obtained as uniform limits on compact subsets of the complex plane of polynomials with real nonpositive zeros only, are described. A class of infinite order differential operators which act between these Frechet spaces is inrtoduced and studied. In particular, it is shown that this class preserves the set of Laguerre entire functions. The results obtained are then used to obtain and to study the solutions of a certain initial value problem. 
Yuri Kozitsky (1 and 2), Lech B. Wolowski (1) ((1) Marie   Curie-Sklodowska University Lublin Poland, (2) Institute for Cond...