Classes of Meromorphic Functions Defined by the Hadamard Product

J. Dziok Institute of Mathematics, University of Rzeszów, ul. Rejtana 16A, 35-310 Rzeszów, Poland Correspondence should be addressed to J. Dziok, [email protected] Received 2 July 2009; Revised 21 November 2009; Accepted 5 January 2010 Academic Editor: Vladimir Mityushev Copyright q 2010 J. Dziok. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. The object of the present paper is to introduce new classes of meromorphic functions with varying argument of coefficients defined by means of the Hadamard product or convolution . Several properties like the coefficients bounds, growth and distortion theorems, radii of starlikeness and convexity, and partial sums are investigated. Some consequences of the main results for wellknown classes of meromorphic functions are also pointed out.