Pitchfork Bifurcation
It is the bifurcation associated with the differential equation: . For the bifurcation is said super-critical and the corresponding equilibrium points are and the last two point exist only for . We can show that is table for and unstable for (as shown in the following figure), while are always stable if they exist.
If , the corresponding equilibrium points are x_{eq} = 0, \pm \sqrt{-r}, but the last two exist only if . The bifurcation is said sub-critical.