On the set of positive solutions for resonant Robin (p, q)-equations

We consider a nonlinear Robin problem driven by the (p, q)-Laplacian and a parametric reaction exhibiting the competition of a concave term and of a resonant perturbation. We prove a bifurcation-type theorem describing the changes in the set of positive solutions as the parameter lambda moves on (R) over circle (+) = (0, +infinity). Also, we determine the continuity properties of the solution multifunction.

Automated summary

The study explores a nonlinear Robin problem driven by the (p, q)-Laplacian and a parametric reaction. It demonstrates a bifurcation-type theorem describing changes in positive solution sets with the parameter lambda on the range (0, +infinity). Additionally, the continuity properties of the solution multifunction are determined.