In this paper, the techniques of partial order theory are used to study the solvability of a class of operator equations Lx = NX, where neither L nor N need to be continuous. Existence and multiplicity results are obtained in complete metric space and Banach space respectively, and then applied to a periodical boundary value problem of an intergro-differential equation.
San Yang LIU, Yu Qiang FENG.
Solvability of a Class of Operator Equations in Partially Ordered Complete Metric Space and in Partially Ordered Banach Space. Acta Mathematica Sinica, Chinese Series, 2005, 48(1): 109-114 https://doi.org/10.12386/A2005sxxb0012