Necessary and sufficient conditions for the existence of periodic solutions in a predator-prey model on time scales

This article explores the existence of periodic solutions for non-autonomous impulsive semi-ratio-dependent predator-prey systems on time scales. Based on a continuous theorem in coincidence degree theory, sharp sufficient and necessary conditions are derived in which most popular monotonic, non-monotonic and predator functional responses are applicable. This article extends the work in [6,10,12,13,134,18,25]