Nonlinear n -Order m -Point Semipositive Boundary Value Problems and Applications

Abstract

In our paper, we consider the positive solutions of the nonlinear $n$ -order $m$ -point semipositive BVP. In this BVP equation, we allow that $f$ can change the symbol for $0<t<1$ ; by using the fixed point index theory, the existence of positive solutions and many positive solutions are obtained under the condition that $f$ is superlinear or sublinear.