On a subclass of tilted starlike functions associated with epicycloid domain

Abstract

This paper investigates a subclass of analytic and univalent functions defined on the open unit disk. A new subclass of tilted starlike functions associated with an epicycloid-shaped domain is defined. These functions are characterized by a subordination condition involving a tilted factor. The study focuses on the analytic characterization of the class, particularly the estimation of initial coefficients. Furthermore, upper bounds are obtained for the Fekete–Szeg¨o functional and the second Hankel determinant. The results not only extend several known findings in the literature but also demonstrate sharpness, since they reduce to known subclasses in special cases, offering new perspectives on the behavior of tilted starlike functions associated with epicycloidal image domains.