Dergiler / Hacettepe Journal of Mathematics and Statistics / 2017 / Cilt: 46 - Sayı: 3

On some new length problem for analytic functions

Sayfa
427–435
Yayın Tarihi
2022-10-18
DOI
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Moreover, we prove that $l(r,f)=\mathcal{O}\left( \log\frac{1}{1-r} \right)$ and that $L(r,f)=\mathcal{O}\left\{ A(r,f)\log \frac{1}{1-r}\right\}^{1/2}$ as $r\to 1$ under weaker assumptions on $f(z)$ than some previous results of this type.

📌 3 Maddede Bu Makale

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Amaç & Hipotez:Let $\mathcal{H}$ denote the class of analytic functions in the unit disk $|z|<1$.
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Temel Bulgular & Veri:Let $C(r,f)$ be the closed curve which is the image of the circle $|z|=r<1$ under the mapping $w=f(z)\in\mathcal{H}$, $L(r,f)$ the length of $C(r,f)$ and let $A(r,f)$ be the area enclosed by $C(r,f)$.
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Sonuç & Katkı:Moreover, we prove that $l(r,f)=\mathcal{O}\left( \log\frac{1}{1-r} \right)$ and that $L(r,f)=\mathcal{O}\left\{ A(r,f)\log \frac{1}{1-r}\right\}^{1/2}$ as $r\to 1$ under weaker assumptions on $f(z)$ than some previous results of this type.
🔬Tür:Araştırma Makalesi
📍Kapsam:Genişletilmiş Akademik Örneklem
⚙️Değişkenler:length problem · convex functions · starlike functions

Abstract

Let $\mathcal{H}$ denote the class of analytic functions in the unit disk $|z|<1$. Let $C(r,f)$ be the closed curve which is the image of the circle $|z|=r<1$ under the mapping $w=f(z)\in\mathcal{H}$, $L(r,f)$ the length of $C(r,f)$ and let $A(r,f)$ be the area enclosed by $C(r,f)$. Let $l(re^{i\theta},f)$ be the length of the image curve of the line segment joining $re^{i\theta}$ and $re^{i(\theta+\pi)}$ under the mapping $w=f(z)$ and let $l(r,f)=\max_{0\leq\theta 2 \pi}l(re^{i\theta},f)$. We find upper bound for $l(r,f)$ for $f(z)$ in some known classes of functions. Moreover, we prove that $l(r,f)=\mathcal{O}\left( \log\frac{1}{1-r} \right)$ and that $L(r,f)=\mathcal{O}\left\{ A(r,f)\log \frac{1}{1-r}\right\}^{1/2}$ as $r\to 1$ under weaker assumptions on $f(z)$ than some previous results of this type.

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Bu Makaleye Atıf Yap

NUNOKAWA, M., SOKOA, J. (2022). On some new length problem for analytic functions. Hacettepe Journal of Mathematics and Statistics, Cilt: 46 - Sayı: 3, 427–435. https://ajindex.com/articles/529947

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Kaynakça (3)

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