On second-order differential subordination for certain meromorphically multivalent functions

Abstract

A new class $\mathcal{R}_n(A,B,\lambda)$ of meromorphically multivalent functions defined by the second-order differential subordination is introduced. Several geometric properties of this new class are studied. The sharp upper bound on $|z|=r<1$ for the functional $\mathrm{Re}\{(\lambda-1)z^{p+1}f'(z)+\frac{\lambda}{p+1}z^{p+2}f''(z)\}$ over the class $\mathcal{R}_n(A,B,0)$ is obtained.

Keywords

• meromorphically multivalent function
• differential subordination
• coefficient estimate
• sharp bound