Second Hankel Determinant for the Class of Analytic Functions Defined by New Differential Operator

In this paper, we introduce a general sed derivative operator D-m (lambda, nu, zeta, omega, alpha)f(z): A -> A as follow: D-m (lambda, nu, zeta, omega, alpha)f(z) = z + Sigma(infinity)(k=2) (nu + k - 1)(zeta + lambda)omega(alpha)/nu alpha(k)z(k). New subclass R-m (lambda, nu, zeta, omega, alpha, theta) defined by the general sed derivative operator D-m (lambda, nu, zeta, omega, alpha) is obtained. Sharp bounds for the nonlinear functional vertical bar a(2)a(4) - a(3)(2)vertical bar are found.