Electronic Journal of Differential Equations, Vol. 2022 (2022), No. 83, pp. 1-11.

Title: Existence of positive periodic solutions for a nonlinear system of second-order ordinary
differential equations
       
Authors: Xiao Han (Jilin Univ., Changchun, China)
         Yujing He (Jilin Univ., Changchun, China)
         Hui Wei (Luoyang Normal Univ., Luoyang, China)
         
Abstract:
This article concerns the positive periodic solutions for a system
of second-order nonlinear ordinary differential equations,
in which the nonlinear term is sublinear in one equation and superlinear
in the other equation.
By using the fixed point theorem of cone expansion and compression
we obtain the existence of positive periodic solutions.

Submitted August 11, 2022. Published December 15, 2022.
Math Subject Classifications: 34C25, 47H10.
Key Words: Existence ofsolutions; positive periodic solutions; fixed point theorem.