On the solvability of parameter-dependent elliptic functional BVPs on annular-like domains

We investigate the existence of nontrivial solutions of parameter-dependent elliptic equations with deviated argument in annular-like domains in Rn, with n ≥ 2, subject to functional boundary conditions. In particular we consider a boundary value problem that may be used to model heat-flow problems. We obtain an existence result by means of topological methods; in particular, we make use of a recent variant in affine cones of the celebrated Birkhoff–Kellogg theorem. Using an ODE argument, we illustrate in an example the applicability of our theoretical result.