S*(φ) and C(φ)-Radii for Some Special Functions

被引：0
作者：
Gangania, Kamaljeet [1 ]
Kumar, S. Sivaprasad [1 ]
机构：
[1] Delhi Technol Univ, Dept Appl Math, Delhi 110042, India
来源：
IRANIAN JOURNAL OF SCIENCE AND TECHNOLOGY TRANSACTION A-SCIENCE | 2022年 / 46卷 / 03期
关键词：
Analytic functions; Radii of starlikeness and convexity; Wright and Mittag-Leffler functions; Legendre polynomials; Lommel and Struve functions; Ramanujan-type entire functions; GEOMETRIC-PROPERTIES; BESSEL-FUNCTIONS; STARLIKENESS; CONVEXITY; RADII;
D O I：
10.1007/s40995-022-01313-6
中图分类号：
O [数理科学和化学]; P [天文学、地球科学]; Q [生物科学]; N [自然科学总论];
学科分类号：
07 ; 0710 ; 09 ;
摘要：
The radius problem explaining the geometric properties of the normalized forms of the special functions has been of special interest among the Geometric function theories. In this paper, we consider the Ma-Minda classes of analytic functions S* (phi) := {f is an element of A : (zf'(z)/f(z))) < phi(z)} and Co(phi) : {f is an element of A : (1 + zf ''(z)/f'(z)) < phi(z)} defined on the unit disk D and show that the classes S*(1+alpha z) and C(1 + az), 0<alpha <= 1 solve the problem of finding the sharp S*(phi)-radii and C(phi)-radii for some normalized special functions, whenever phi(-) = 1 - a. Radius of strongly starlikeness is also considered.
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页码：955 / 966
页数：12
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