Turkish Journal of Mathematics and Computer Science, cilt.15, sa.1, ss.71-78, 2023 (Scopus, TRDizin)
This paper deals with a class of nonlinear fractional boundary value problems at resonance with Caputo-Fabrizio fractional derivative. We establish some new necessary conditions for the existence of positive solutions for the fractional boundary value problems at resonance by using the Leggett-Williams norm-type theorem for coincidences due to O’ Regan and Zima. Some examples are constructed to support our results.