• Title/Summary/Keyword: strongly starlike functions

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ON SUFFICIENT CONDITIONS FOR CARATHÉODORY FUNCTIONS WITH THE FIXED SECOND COEFFICIENT

  • Kwon, Oh Sang
    • Honam Mathematical Journal
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    • v.41 no.2
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    • pp.227-242
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    • 2019
  • In the present paper, we derive several sufficient conditions for $Carath{\acute{e}}odory$ functions in the open unit disk ${\mathbb{D}}:=\{z{\in}{\mathbb{C}}:{\mid}z{\mid}<1\}$ under the constraint that the second coefficient of the function is preassigned. And, we obtain some sufficient conditions for strongly starlike functions in ${\mathbb{D}}$.

ON THE $FEKETE-SZEG\"{O}$ PROBLEM FOR STRONGLY $\alpha$-LOGARITHMIC CLOSE-TO-CONVEX FUNCTIONS

  • Cho, Nak-Eun
    • East Asian mathematical journal
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    • v.21 no.2
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    • pp.233-240
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    • 2005
  • Let $CS^{\alpha}(\beta)$ denote the class of normalized strongly $\alpha$-logarithmic close-to-convex functions of order $\beta$, defined in the open unit disk $\mathbb{U}$ by $$\|arg\{\(\frac{f(z)}{g(z)}\)^{1-\alpha}\(\frac{zf'(z)}{g(z)\)^{\alpha}\}\|\leq\frac{\pi}{2}\beta,\;(\alpha,\beta\geq0)$$ where $g{\in}S^*$ the class of normalized starlike functions. In this paper, we prove sharp $Fekete-Szeg\"{o}$ inequalities for functions $f{\in}CS^{\alpha}(\beta)$.

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GEOMETRIC PROPERTIES ON (j, k)-SYMMETRIC FUNCTIONS RELATED TO STARLIKE AND CONVEX FUNCTION

  • Gochhayat, Priyabrat;Prajapati, Anuja
    • Communications of the Korean Mathematical Society
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    • v.37 no.2
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    • pp.455-472
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    • 2022
  • For j = 0, 1, 2,…, k - 1; k ≥ 2; and - 1 ≤ B < A ≤ 1, we have introduced the functions classes denoted by ST[j,k](A, B) and K[j,k](A, B), respectively, called the generalized (j, k)-symmetric starlike and convex functions. We first proved the sharp bounds on |f(z)| and |f'(z)|. Various radii related problems, such as radius of (j, k)-symmetric starlikeness, convexity, strongly starlikeness and parabolic starlikeness are determined. The quantity |a23 - a5|, which provide the initial bound on Zalcman functional is obtained for the functions in the family ST[j,k]. Furthermore, the sharp pre-Schwarzian norm is also established for the case when f is a member of K[j,k](α) for all 0 ≤ α < 1.

MITTAG LEFFLER FUNCTIONS ASSOCIATED WITH FUNCTIONS THAT MAP OPEN UNIT DISC ONTO A SECTOR OF THE RIGHT-HALF PLANE

  • AFIS SALIU;KANWAL JABEEN;SEMIU OLADIPUPO OLADEJO;OLAIDE YETUNDE SAKA-BALOGUN
    • Journal of applied mathematics & informatics
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    • v.41 no.5
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    • pp.937-946
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    • 2023
  • In this present work, we inaugurated subclasses of analytic functions which are associated with generalized Mittag Leffler Functions. Inclusion implications and integral preserving properties under the Bernardi integral operator are investigated. Some consequences of these findings are also illustrated.