Reciprocal starlikeness of order α > 1 of meromorphic functions

Priya G. Krishnan,V. Ravichandran, P. Saikrishnan

A meromorphic function f defined on the punctured unit disc D\{0} with a simple pole at the origin with residue 1 is called starlike of reciprocal order α > 1 if the function - f(z)/(zf '(z)) has real part less than α. We use the theory of differential subordination to find various sufficient conditions for certain meromorphic functions to be starlike of reciprocal order α > 1. Also, for certain meromorphic functions f, we find sufficient conditions for f(z)/(zf '(z)) to be in a disc centered at -1 of radius α - 1. 

Advanced Studies: Euro-Tbilisi Mathematical Journal, Vol. 19(1) (2026), pp. 199-215