Starlikeness of Analytic Functions with Subordinate Ratios

Rosihan M. Ali; Kanika Sharma; V. Ravichandran

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arXiv · 2101.01617

Starlikeness of Analytic Functions with Subordinate Ratios

Rosihan M. Ali·Kanika Sharma·V. Ravichandran

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Abstract

Let $h$ be a non-vanishing analytic function in the open unit disc with $h(0)=1$. Consider the class consisting of normalized analytic functions $f$ whose ratios $f(z)/g(z)$, $g(z)/z p(z)$, and $p(z)$ are each subordinate to $h$ for some analytic functions $g$ and $p$. The radius of starlikeness is obtained for this class when $h$ is chosen to be either $h(z)=\sqrt{1+z}$ or $h(z)=e^z$. Further $\mathcal{G}$-radius is also obtained for each of these two classes when $\mathcal{G}$ is a particular widely studied subclass of starlike functions. These include $\mathcal{G}$ consisting of the Janowski starlike functions, and functions which are parabolic starlike.

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BibTeX RIS

Rosihan M. Ali, Kanika Sharma, V. Ravichandran. 2021-01-05. Starlikeness of Analytic Functions with Subordinate Ratios. https://arxiv.org/abs/2101.01617

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