Positive solutions of second-order two-delay differential systems with twin-parameter

The paper is concerned with the existence of positive solutions for a second order two-delay differential systems with twin-parameter. Firstly, we present some sufficient conditions with the twin-parameter belonging to an open rectangular region (eigenvalue region) to ensure the existence of positive solutions for the differential systems with singularity. Secondly, we deal with the superlinear semipositone problem of the differential systems and establish the existence of positive solutions for the systems. The proofs are based on a fixed-point theorem in cones.