An Upper Bound to the Second Hankel Determinant for Functions in Mocanu Class

Upper Bound of Second Hankel Determinant for Certain Subclasses of Analytic Functions

“…Similar to the above discussions defined as different classes of analytic functions, we can also refer to [39][40][41][42][43][44][45][46][47][48][49].…”

Second Hankel determinant for certain class of bi-univalent functions defined by Chebyshev polynomials

“…Recently, Kowalczyk et al [24] discussed the developments involving the Fekete-Szegö functional |a 3 −δa 2 2 |, where 0 ≤ δ ≤ 1 as well as the corresponding Hankel determinant for the Taylor-Maclaurin coefficients {a n } n∈N\{1} of normalized univalent functions of the form (1.1). Similarly, several authors have investigated upper bounds for the Hankel determinant of functions belonging to various subclasses of univalent functions [1,2,13,25,27,29] and the references therein. On the other hand, Zaprawa [49,50] extended the study on Fekete-Szegö problem to some specific classes of bi-univalent functions.…”

Fekete-Szegö problem and Second Hankel Determinant for a class of bi-univalent functions

“…In 1969, Keogh and Merkes [18] discussed the Fekete-Szegö problem for the classes starlike and convex functions. Recently, several authors have investigated upper bounds for the Hankel determinant of functions belonging to various subclasses of univalent functions [2,9,19,21] and the references therein. On the other hand, Zaprawa [29,30] extended the study of Fekete-Szegö problem to certain subclasses of bi-univalent function class σ.…”