About some differential sandwich theorems using a multiplier transformation and Ruscheweyh derivative.

In this work we study a new operator IRλ,lm,n defined as the Hadamard product of the multiplier transformation I (m, λ, l) and Ruscheweyh derivative R¹, given by IRλ,lm,n : A → A, IRλ,lm,n (z) = (I (m, λ, l) * Rn)f(z) and An = {f ∈ H (U) : f(z) = z + an+1zn+1 + ..., z ∈ U} is the class of normalized analytic functions with A1 = A. The purpose of this paper is to derive certain subordination and superordination results involving the operator IRλ,lm,n and we establish differential sandwich-type theorems. [ABSTRACT FROM AUTHOR]