Upper and Lower Solutions Method for a Class of Singular Fractional Boundary Value Problems with p‐Laplacian Operator

The upper and lower solutions method is used to study the p ‐Laplacian fractional boundary value problem , 0 < t < 1, u (0) = 0, u (1) = a u ( ξ ), , and , where 1 < α , γ ⩽ 2, 0 ⩽ a , b ⩽ 1, 0 < ξ , η < 1. Some new results on the existence of at least one positive solution are obtained. It is valuable to point out that the nonlinearity f can be singular at t = 0,1 or u = 0.