Existence of periodic solutions of partial neutral functional differential equations with unbounded delay

In this article we establish a result of existence of periodic solutions for the class of quasi-linear partial neutral functional differential equations with unbounded delay that can be described as the abstract functional differential equation (d/dt)(x(t) + F(t, x(t))) = Ax(t) + G(t, x(t)), where A is the infinitesimal generator of a strongly continuous semigroup of linear operators on a Banach space and F and G are appropriate functions defined on a phase space. (C) 1998 Academic Press.