A Comparison Result for the Nabla Fractional Difference Operator

Abstract

This article establishes a comparison principle for the nabla fractional difference operator ∇ρ(a)ν, 1ν2. For this purpose, we consider a two-point nabla fractional boundary value problem with separated boundary conditions and derive the corresponding Green’s function. I prove that this Green’s function satisfies a positivity property. Then, I deduce a relatively general comparison result for the considered boundary value problem.

Keywords

• nabla fractional boundary value problem
• separated boundary conditions
• Green’s function
• positivity property
• comparison principle