• Title/Summary/Keyword: starlike

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UNIVALENT FUNCTIONS WITH POSITIVE COEFFICIENTS INVOLVING POISSON DISTRIBUTION SERIES

  • Murugusundaramoorthy, Gangadharan
    • Honam Mathematical Journal
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    • v.40 no.3
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    • pp.529-538
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    • 2018
  • The purpose of the present paper is to establish connections between various subclasses of analytic univalent functions by applying certain convolution operator involving Poisson distribution series. To be more precise,we investigate such connections with the classes of analytic univalent functions with positive coefficients in the open unit disk.

Suffciency Conditions for Hypergeometric Functions to be in a Subclasses of Analytic Functions

  • Aouf, Mohamed Kamal;Mostafa, Adela Osman;Zayed, Hanaa Mousa
    • Kyungpook Mathematical Journal
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    • v.56 no.1
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    • pp.235-248
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    • 2016
  • The purpose of this paper is to introduce sufficient conditions for (Gaussian) hypergeometric functions to be in various subclasses of analytic functions. Also, we investigate several mapping properties involving these subclasses.

On Applications of Differential Subordination to Certain Subclass of Multivalent Functions

  • Aghalary, Rasoul;Wang, Zhi-Gang
    • Kyungpook Mathematical Journal
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    • v.49 no.2
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    • pp.265-281
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    • 2009
  • In the present paper, we introduce and investigate a new subclass of multivalent functions associated with the Cho-Kwon-Srivastava operator $\tau^{\lambda}_p(a,c)$. Such results as inclusion relationships, convolution properties and criteria for starlikeness are proved. Relevant connections of the results presented here with those obtained in earlier works are also pointed out.

FEKETE-SZEGÖ INEQUALITY FOR A SUBCLASS OF NON-BAZILEVIĆ FUNCTIONS INVOLVING CHEBYSHEV POLYNOMIAL

  • Al-khafaji, Saba N.;Bulut, Serap;Juma, Abdul Rahman S.
    • Honam Mathematical Journal
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    • v.43 no.3
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    • pp.503-511
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    • 2021
  • In this present work, we obtain certain coefficients of the subclass 𝓗λ,𝛄(s, b, n) of non-Bazilević functions and estimate the relevant connection to the famous classical Fekete-Szegö inequality of functions belonging to this class.

SYMMETRIC TOEPLITZ DETERMINANTS ASSOCIATED WITH A LINEAR COMBINATION OF SOME GEOMETRIC EXPRESSIONS

  • Ahuja, Om P.;Khatter, Kanika;Ravichandran, V.
    • Honam Mathematical Journal
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    • v.43 no.3
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    • pp.465-481
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    • 2021
  • Let f be the function defined on the open unit disk, with f(0) = 0 = f'(0) - 1, satisfying Re (αf'(z) + (1 - α)zf'(z)/f(z)) > 0 or Re (αf'(z) + (1 - α)(1 + zf"(z)/f'(z)) > 0 respectively, where 0 ≤ α ≤ 1. Estimates for the Toeplitz determinants have been obtained when the elements are the coefficients of the functions belonging to these two subclasses.

CERTAIN SUBCLASSES OF ANALYTIC FUNCTIONS ASSOCIATED WITH THE CHEBYSHEV POLYNOMIALS

  • BULUT, Serap;MAGESH, Nanjundan;BALAJI, Vittalrao Kupparao
    • Honam Mathematical Journal
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    • v.40 no.4
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    • pp.611-619
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    • 2018
  • In this paper, we obtain initial coefficient bounds for an unified subclass of analytic functions by using the Chebyshev polynomials. Furthermore, we find the Fekete-$Szeg{\ddot{o}}$ result for this class. All results are sharp. Consequences of the results are also discussed.

GEOMETRIC PROPERTIES OF GENERALIZED DINI FUNCTIONS

  • Deniz, Erhan;Goren, Seyma
    • Honam Mathematical Journal
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    • v.41 no.1
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    • pp.101-116
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    • 2019
  • In this paper our aim is to establish some geometric properties (like starlikeness, convexity and close-to-convexity) for the generalized and normalized Dini functions. In order to prove our main results, we use some inequalities for ratio of these functions in normalized form and classical result of Fejer.

ON GEOMETRIC PROPERTIES OF THE MITTAG-LEFFLER AND WRIGHT FUNCTIONS

  • Das, Sourav;Mehrez, Khaled
    • Journal of the Korean Mathematical Society
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    • v.58 no.4
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    • pp.949-965
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    • 2021
  • The main focus of the present paper is to present new set of sufficient conditions so that the normalized form of the Mittag-Leffler and Wright functions have certain geometric properties like close-to-convexity, univalency, convexity and starlikeness inside the unit disk. Interesting consequences and examples are derived to support that these results are better than the existing ones and improve several results available in the literature.