UNIFORM ULTIMATE BOUNDEDNESS AND PERIODIC SOLUTIONS TO NONLINEAR INTEGRO-DIFFERENTIAL EQUATIONS
Jiabu Dishen (Dept. of Basic Sciences, the Chinese People’s Armed Police Forces Academy, Langfang 065000, Hebei)
In this paper, the existence of periodic solution to nonlinear integro-differential equations with infinite delay is studied in the phase space (Cg,|·|g). We prove that the g-uniformly ultimately bounded solutions implies the existence of periodic solutions using Horn's fixed point theorem. Some known results are generalized, including the famous Yoshizawa's theorem.