Publishing house / Journals and Serials / Annales Polonici Mathematici / All issues

Abstract

We determine coefficient estimates for α-spiral functions of order ϱ with respect to N-symmetric points (|α| = π/2, 0 ≤ ϱ = 1$ and N is a positive integer). Sharp coefficient bounds are also obtained for functions of the form $f(z)^{-t}$, where t is a positive integer and f(z) is an α-spiral function of order ϱ. Using this we deduce coefficient estimates for inverses of univalent α-spiral and meromorphic univalent α-spiral functions with vanishing early coefficients.