Papageorgiou, Nikolaos S.Winkert, Patrick2021-03-152021-03-152020-09-290095-4616https://depositonce.tu-berlin.de/handle/11303/12822http://dx.doi.org/10.14279/depositonce-11622We consider a nonlinear Dirichlet problem driven by the ( p ,  q )-Laplacian with 1 < q < p . The reaction is parametric and exhibits the competing effects of a singular term and of concave and convex nonlinearities. We are looking for positive solutions and prove a bifurcation-type theorem describing in a precise way the set of positive solutions as the parameter varies. Moreover, we show the existence of a minimal positive solution and we study it as a function of the parameter.en510 Mathematikminimal positive solutionnonlinear maximum principlenonlinear regularity theorysingular and concave-convex termsstrong comparison theoremsArticle1432-0606