Positive periodic solutions of second-or
β
Jun Wu; Zhicheng Wang
π
Article
π
2008
π
Elsevier Science
π
English
β 282 KB
By employing the Deimling fixed point index theory, we consider a class of second-order nonlinear differential systems with two parameters (Ξ», Β΅) β R 2 + \ {(0, 0)}. We show that there exist three nonempty subsets of R 2 + \ {(0, 0)}: Ξ , β 1 and β 2 such that R 2 + \ {(0, 0)} = Ξ βͺ β 1 βͺ β 2 and th