Figure 1From: Complex dynamics in an SIS epidemic model with nonlinear incidenceGraphs of different incidence rate functions. (a) Non-monotone incidence \(g_{1}(I)=\frac{\kappa I}{1+\alpha I^{2}}\). (b) Nonlinear incidence \(g_{2}(I)=\frac{\kappa I^{2}}{1+\alpha I^{2}}\). (c) Nonlinear and non-monotone incidence rate \(G(I)=\frac {aI^{2}}{I^{2}+c}+\frac{bI}{I^{2}+c}\)Back to article page