Multiple positive solutions to boundary value problems for second-order delay differential equations
The authors use fixed-point theorems in cones to study the existence of solutions to boundary value problems for second-order delay differential equations of the form \[ y''((t) + f(t,y(t-\tau))=0,\quad 0<t<1,\quad y(t)=0,\;-\tau \leq t \leq 0,\;y(1) = 0, \] for suitably small \(\tau\). The main result in this work generalizes a result due to \textit{Z. Liu} and \textit{F. Li} [J. Math. Anal. Appl. 203, No.~3, 610-625 (1996; Zbl 0878.34016)] for ordinary differential equations.
existence of multiple positive solutions
scientific article; zbMATH DE number 1781921