Journal of Function Spaces (Jan 2021)

Logarithmic Coefficient Bounds and Coefficient Conjectures for Classes Associated with Convex Functions

  • Davood Alimohammadi,
  • Ebrahim Analouei Adegani,
  • Teodor Bulboacă,
  • Nak Eun Cho

DOI
https://doi.org/10.1155/2021/6690027
Journal volume & issue
Vol. 2021

Abstract

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It is well-known that the logarithmic coefficients play an important role in the development of the theory of univalent functions. If S denotes the class of functions fz=z+∑n=2∞anzn analytic and univalent in the open unit disk U, then the logarithmic coefficients γnf of the function f∈S are defined by logfz/z=2∑n=1∞γnfzn. In the current paper, the bounds for the logarithmic coefficients γn for some well-known classes like C1+αz for α∈0,1 and CVhpl1/2 were estimated. Further, conjectures for the logarithmic coefficients γn for functions f belonging to these classes are stated. For example, it is forecasted that if the function f∈C1+αz, then the logarithmic coefficients of f satisfy the inequalities γn≤α/2nn+1,n∈ℕ. Equality is attained for the function Lα,n, that is, logLα,nz/z=2∑n=1∞γnLα,nzn=α/nn+1zn+⋯,z∈U.