Avery, Richard; Eloe, Paul; Henderson, Johnny A Leggett-Williams type theorem applied to a fourth order problem. (English) Zbl 1273.34024 Commun. Appl. Anal. 16, No. 4, 579-588 (2012). Summary: We apply an extension of a Leggett-Williams type fixed point theorem to a two-point boundary value problem for a fourth order ordinary differential equation. The fixed point theorem employs concave and convex functionals defined on a cone in a Banach spstce. Inequalities that extend the notion of concavity to fourth order differential inequalities are derived and employed to provide the necessary estimates. Symmetry is employed in the construction of the appropriate Banach space. Cited in 2 Documents MSC: 34B15 Nonlinear boundary value problems for ordinary differential equations 34B27 Green’s functions for ordinary differential equations 47H10 Fixed-point theorems PDFBibTeX XMLCite \textit{R. Avery} et al., Commun. Appl. Anal. 16, No. 4, 579--588 (2012; Zbl 1273.34024)