TY - JOUR ID - Totoi2011 LB - Totoi2011 AU - Totoi, Alina TI - On some classes of meromorphic functions defined by subordination and superordination ST - On some classes of meromorphic functions defined by subordination and superordination JO - Opuscula Math. JA - Opuscula Math. JF - Opuscula Mathematica PY - 2011 VL - 31 IS - 4 SP - 651 EP - 668 DO - http://dx.doi.org/10.7494/OpMath.2011.31.4.651 UR - http://dx.doi.org/10.7494/OpMath.2011.31.4.651 AB - Let \(p\in \mathbb{N}^*\) and \(\beta,\gamma\in \mathbb{C}\) with \(\beta\neq 0\) and let \(\Sigma_p\) denote the class of meromorphic functions of the form \(g(z)=\frac{a_{-p}}{z^p}+a_0+a_1 z+\ldots,\,z\in \dot U\), \(a_{-p}\neq 0\). We consider the integral operator \(J_{p,\beta,\gamma}:K_{p,\beta,\gamma}\subset\Sigma_p\to \Sigma_p\) defined by \[J_{p,\beta,\gamma}(g)(z)=\left[\frac{\gamma-p\beta}{z^\gamma }\int_0^zg^{\beta}(t) t^{\gamma-1}dt\right]^{\frac{1}{\beta}},\,g\in K_{p,\beta,\gamma},\,z\in \dot U.\] We introduce some new subclasses of the class \(\Sigma_p\), associated with subordination and superordination, such that, in some particular cases, these new subclasses are the well-known classes of meromorphic starlike functions and we study the properties of these subclasses with respect to the operator \(J_{p,\beta,\gamma}\). KW - meromorphic functions KW - integral operators KW - subordination KW - superordination SN - 1232-9274 ER -