Zobrazeno 1 - 10
of 287
pro vyhledávání: '"Nak Eun Cho"'
Publikováno v:
AIMS Mathematics, Vol 9, Iss 6, Pp 15761-15781 (2024)
In the current article, we consider a class of bounded turning functions associated with the cosine hyperbolic function and give some results containing coefficient functionals using the familiar Carathéodory functions. An improvement on the bound o
Externí odkaz:
https://doaj.org/article/02cbe2c489d24cf997f7c6ff8a37ecf7
Publikováno v:
AIMS Mathematics, Vol 9, Iss 3, Pp 5466-5479 (2024)
In the present paper, we investigated some conditions to be in the class of Carathéodory functions by using the concept of the first-order differential subordinations. Moreover, various interesting special cases were considered in the geometric func
Externí odkaz:
https://doaj.org/article/cc9c1f5bb3da4f9b92b0e494d4327da8
Publikováno v:
Journal of Inequalities and Applications, Vol 2023, Iss 1, Pp 1-11 (2023)
Abstract Due to the major importance of the study of the logarithmic coefficients for univalent functions, in this paper we find the sharp upper bounds for some expressions associated with logarithmic coefficients of functions that belong to some wel
Externí odkaz:
https://doaj.org/article/c8e93850674a4dc6b245248821a80fac
Publikováno v:
AIMS Mathematics, Vol 8, Iss 12, Pp 29535-29554 (2023)
In the current article, we introduced new subclasses of bi-univalent functions associated with bounded boundary rotation. For these new classes, the authors first obtained two initial coefficient bounds. They also verified the special cases where the
Externí odkaz:
https://doaj.org/article/1626d3bd9ea1485492a126c0f674df05
Publikováno v:
AIMS Mathematics, Vol 8, Iss 10, Pp 23146-23163 (2023)
In this article, we introduce a new class of analytic functions in the open unit disc that are closely related to functions that are starlike with respect to a boundary point. For this new class of functions, we obtain representation theorem, interes
Externí odkaz:
https://doaj.org/article/3e17604110b643b690ffbdc1dd9d790c
Publikováno v:
AIMS Mathematics, Vol 8, Iss 9, Pp 21732-21745 (2023)
The logarithmic coefficients of univalent functions play an important role in different estimates in the theory of univalent functions. In this paper, due to the significant importance of the study of these coefficients, we find the upper bounds for
Externí odkaz:
https://doaj.org/article/bcadffb2813e482e8fe5c7f06c919857
Publikováno v:
Journal of Inequalities and Applications, Vol 2022, Iss 1, Pp 1-16 (2022)
Abstract Our purpose in the present investigation is to study certain geometric properties such as the close-to-convexity, convexity, and starlikeness of the hypergeometric function z 1 F 2 ( a ; b , c ; z ) $z{}_{1}F_{2}(a;b,c;z)$ in the open unit d
Externí odkaz:
https://doaj.org/article/ce32bd84804e421da3582fef837f550a
Publikováno v:
Axioms, Vol 13, Iss 1, p 25 (2023)
The objective of the present article is to introduce new subclasses of bi-Bazilevič functions, bi-quasi-convex functions and α-exponentially bi-convex functions involving functions with bounded boundary rotation of order ν. For the above-said newl
Externí odkaz:
https://doaj.org/article/462e2d2317124b0aad9e9533051c78c4
Autor:
Muhammad Ghaffar Khan, Nak Eun Cho, Timilehin Gideon Shaba, Bakhtiar Ahmad, Wali Khan Mashwani
Publikováno v:
AIMS Mathematics, Vol 7, Iss 2, Pp 3133-3149 (2022)
The main objective of the present article is to define the class of bounded turning functions associated with modified sigmoid function. Also we investigate and determine sharp results for the estimates of four initial coefficients, Fekete-Szegö fun
Externí odkaz:
https://doaj.org/article/6be37b7e685842f1b5398830603d368a
Publikováno v:
Axioms, Vol 12, Iss 8, p 775 (2023)
In the present paper, we give a new simple proof on the sharp bounds of coefficient functionals related to the Carathéodory functions and make a correction on the extremal functions. The result is further used to investigate some initial coefficient
Externí odkaz:
https://doaj.org/article/8f48bd80e5a64775b9e45e5c10f106a9