Jiang, Yongxin2021-11-052021-11-052019-04-10Jiang, Y. (2019). Periodic solutions of second-order non-autonomous dynamical systems with vanishing Green's functions. <i>Electronic Journal of Differential Equations, 2019</i>(47), pp. 1-12.1072-6691https://hdl.handle.net/10877/14780In this article, we study the existence and multiplicity of positive periodic solutions for second-order non-autonomous dynamical systems when Green's functions are non-negative. The proofs are based on a nonlinear alternative principle of Leray-Schauder and the fixed point theorem in cones. Some recent results in the literature are generalized and improved.Text12 pages1 file (.pdf)enAttribution 4.0 InternationalVanishing Green's functionLeray-Schauder alternativeFixed point theorem in conesArticle