We look for bounded periodic solutions for a parametric fractional problem involving a continuous nonlinearity with subcritical growth. By using a variant of Caffarelli and Silvestre extension method adapted to the periodic case and variational tools we prove the existence of at least three bounded periodic solutions when the parameter varies in an appropriate range.
"A multiplicity result for a non-local parametric problem with periodic boundary conditions." Ark. Mat. 58 (1) 1 - 18, April 2020. https://doi.org/10.4310/ARKIV.2020.v58.n1.a1