Bifurcation Analysis of an SIR Model with Logistic Growth, Nonlinear Incidence, and Saturated Treatment

Figure 11

Phase portrait of the system near the BT point of codimension 3 when a supercritical Hopf bifurcation occurs. In (a), the endemic equilibrium is stable. In (b), the endemic equilibrium is unstable and there is a stable limit cycle.

(a)

(b)