Sun, Jiebao; Jin, Chunhua; Ke, Yuanyuan Existence of non-trivial nonnegative periodic solutions for a nonlinear diffusion system. (English) Zbl 1142.35322 Northeast. Math. J. 23, No. 2, 167-175 (2007). Summary: In this paper, by the method of upper and lower solution, the authors establish the existence of the non-trivial nonnegative periodic solutions for a class of degenerate diffusion system arising from dynamics of biological groups. Cited in 1 Document MSC: 35B10 Periodic solutions to PDEs 35K50 Systems of parabolic equations, boundary value problems (MSC2000) 35K57 Reaction-diffusion equations 35K65 Degenerate parabolic equations Keywords:periodic solution; upper and lower solution PDFBibTeX XMLCite \textit{J. Sun} et al., Northeast. Math. J. 23, No. 2, 167--175 (2007; Zbl 1142.35322)