Periodic solutions for a semi-ratio-dependent predator–prey system with nonmonotonic functional response and time delay

By using the continuation theorem of coincidence degree theory, the existence of a positive periodic solution for the semi-ratio-dependent predator–prey system with nonmonotonic functional responses and time delay is established. Further, by constructing a Lyapunov functional, a set of easily verifiable sufficient conditions are derived for the uniqueness and global stability of positive periodic solutions to the system. Finally, some numerical simulations are carried out to support the theoretical analysis of the research.