Some orders and types of generalized Hadamard product of entire functions (Q1864529)

Given two entire functions \(f_j(z)=\sum_{n=0}^\infty a_{n,j}z^n\), \(j=1,2\), and numbers \(\mu\), \(\nu>0\), the authors present upper estimates of the order and type, logarithmic order and type, and \(q\)--order and \(q\)--type of the generalized Hadamard product \((f_1\Delta f_2)(\mu,\nu;z):=\sum_{n=0}^\infty a_{n,1}^\mu a_{n,2}^\nu z^n\).