Minhós, F.; Gyulov, T.; Santos, A. I. Existence and location result for a fourth order boundary value problem. (English) Zbl 1157.34310 Discrete Contin. Dyn. Syst. 2005, Suppl., 662-671 (2005). Summary: We prove an existence and location result for the fourth order nonlinear equation \[ u^{(i \upsilon)} = f(t, u, u', u'', u'''),\quad 0 < t < 1, \] with the Lidstone boundary conditions \[ u(0) = u''(0) = u(1) = u''(1) = 0, \] where \(f: [0,1] \times \mathbb{R}^{4} \to \mathbb R\) is a continuous function satisfying a Nagumo type condition. The existence of at least one solution lying between a pair of well ordered lower and upper solutions is obtained by using an a priori estimate, lower and upper solutions method and degree theory. Cited in 17 Documents MSC: 34B15 Nonlinear boundary value problems for ordinary differential equations Keywords:fourth order boundary value problem; Nagumo condition; a priori estimate; a pair of lower and upper solutions; degree theory PDFBibTeX XMLCite \textit{F. Minhós} et al., Discrete Contin. Dyn. Syst. 2005, 662--671 (2005; Zbl 1157.34310)