On the analog of the Sălăgean class for Dirichlet series and the solutions of one linear differential equation with exponential coefficients

• Дата: 2025
• Автори: Sheremeta, M., Mulyava, O., Medvedev, M., Шеремета, Мирослав, Мулява, Оксана, Медвєдєв, Микола
• Формат: Стаття
• Мова: Українська
• Опубліковано: Institute of Mathematics, NAS of Ukraine 2025
• Онлайн доступ: https://umj.imath.kiev.ua/index.php/umj/article/view/8555
• Назва журналу: Ukrains’kyi Matematychnyi Zhurnal

UDC 517.537 In his study of the geometric properties of functions analytic in a disk ${\mathbb D} = \{z\colon |z|<1\},$ G. S. Sălăgean introduced a class $S_j(\alpha)$ of functions $f(z) = z + \sum _{k = 2}^{\infty}f_kz^k$ such that $\operatorname{Re} \frac{D^{j + 1}f(z)}{D^{j}f(z)} &...