Dynamic behaviors of a modified SIR model in epidemic diseases using nonlinear incidence and recovery rates
Fig 4
Graph of h(I) with different signs of Δ1 when b1 < 0.
When I2 = Hm, I2 = HM or I2 = HM = Hm, Hopf bifurcation occurs. BT bifurcation of codimension 2 occurs when I* = Hm or I* = HM and BT bifurcation of codimension 3 occurs when I* = Hm = HM.