Normal Forms for Retarded Functional Differential Equations with Parameters and Applications to Hopf Bifurcation

The paper addresses, for retarded functional differential equations (FDEs) with parameters, the computation of normal forms associated with the flow on a finite-dimensional invariant manifold tangent to an invariant space for the infinitesimal generator of the linearized equation at a singularity. The analysis is based on the theory previously developed for FDEs without parameters by considering an extension of a phase space appropriate to the computation of these normal forms. As an application, the generic Hopf bifurcation for scalar retarded FDEs is considered