On the Gelfond – Leont’ev – Sǎlǎgean and Gelfond – Leont’ev – Ruscheweyh operators and analytic continuation of functions

• Date: 2022
• Main Authors: Sheremeta , M. M, Шеремета, М. М.
• Format: Article
• Language: Ukrainian
• Published: Institute of Mathematics, NAS of Ukraine 2022
• Online Access: https://umj.imath.kiev.ua/index.php/umj/article/view/7058
• Journal Title: Ukrains’kyi Matematychnyi Zhurnal

UDC 517.537 Let $A_{\lambda} (0)$ denote the class of power series $g(z) = \sum^{\infty}_{k=0} g^k z_k$ such that $|g_k| \leq \lambda_k| g_1|$ for all $k \geq 1$, where $\lambda = (\lambda_k)$ is a sequence of positive numbers. We obtain necessary and sufficient conditions imposed on a function $l$...