We study the singular fractional-order boundary-value problem with a sign-changing nonlinear term , , where , and with and , satisfying , is the standard Riemann-Liouville derivative, is a sign-changing continuous function and may be unbounded from below with respect to , and is continuous. Some new results on the existence of nontrivial solutions for the above problem are obtained by computing the topological degree of a completely continuous field.
"Solutions of Sign-Changing Fractional Differential Equation with the Fractional Derivatives." Abstr. Appl. Anal. 2012 (SI11) 1 - 16, 2012. https://doi.org/10.1155/2012/797398