on dynamics of an siqr model as a system of fractional differential equations

The main purpose of this paper is to develop and analyse a fractional siqrepidemic model with caputo-fabrizio derivative. it is shown that the model to havea disease-free and an endemic equilibrium point. some conditions are derived for theexistence and stability of these equilibrium points. finally, three-step fractional adams-bashforth method applied to the model and some numerical simulations are illustratethe results.