Classification of f-biharmonic submanifolds in Lorentz space forms

In this paper, -biharmonic submanifolds with parallel normalized mean curvature vector field in Lorentz space forms are discussed. When is a constant, we prove that such submanifolds have parallel mean curvature vector field with the minimal polynomial of the shape operator of degree . When is a function, we completely classify such pseudo-umbilical submanifolds.