Li, Yongxiang Positive periodic solutions of first and second order ordinary differential equations. (English) Zbl 1073.34041 Chin. Ann. Math., Ser. B 25, No. 3, 413-420 (2004). The paper deals with the existence of positive \(\omega\)-periodic solutions of the second-order differential equation \[ -u^{\prime \prime}(t) = f(t,u(t)), \quad t \in \mathbb{R}, \] as well as first-order ordinary differential equations. The main tool is the fixed-point index theory in cones. Reviewer: Emil Minchev (Tokyo) Cited in 1 ReviewCited in 16 Documents MSC: 34C25 Periodic solutions to ordinary differential equations 47H10 Fixed-point theorems 34B18 Positive solutions to nonlinear boundary value problems for ordinary differential equations Keywords:positive periodic solution; cone; fixed-point index PDF BibTeX XML Cite \textit{Y. Li}, Chin. Ann. Math., Ser. B 25, No. 3, 413--420 (2004; Zbl 1073.34041) Full Text: DOI OpenURL References: This reference list is based on information provided by the publisher or from digital mathematics libraries. Its items are heuristically matched to zbMATH identifiers and may contain data conversion errors. It attempts to reflect the references listed in the original paper as accurately as possible without claiming the completeness or perfect precision of the matching.