Determining codimension of Bogdanov-Takens and Bautin bifurcations via simplest normal form computation

In solving real-world problems, determining the codimension of Bogdanov-Takens (BT) and Bautin (generalized Hopf) bifurcations can be very challenging, even for simple two-dimensional dynamical systems. This difficulty becomes particularly evident when the number of system parameters exceeds the codimension of the bifurcations. Such challenges are closely linked to analyzing complex dynamics, such as the bifurcation of multiple limit cycles and homoclinic/heteroclinic bifurcations. In this paper, we use two population systems to demonstrate a systematic approach for determining the conditions that define the codimension of BT and Bautin bifurcations.