BOUNDEDNESS OF L-INDEX IN JOINT VARIABLES FOR SUM OF ENTIRE FUNCTIONS

Abstract

In the paper, we present sufficient conditions of boundedness of L-index in joint variables for a sum of entire functions, where L : C n → R n + is a continuous function, R+ = (0, +∞). They are applicable to a very wide class of entire functions because for every entire function F in C n with bounded multiplicities of zero points there exists a positive continuous function L such that F has bounded L-index in joint variables. Our propositions are generalizations of Pugh’s result obtained for entire functions of one variable of bounded index.