Hopf bifurcation in discrete-time systems via a frequency domain approach

The application of the Hopf bifurcation theorem (HBT) for maps is presented in this paper. The invariant cycle emerging from the bifurcation is approximated using an analogous version of the graphical Hopf theorem (GHT) for continuous-time systems. This technique is formulated in the so-called frequency domain and it involves the use of the Nyquist stability criterion for discrete-time systems. An application example is included for illustration.