par Abatangelo, Nicola ;Jarohs, Sven;Saldaña, Alberto
Référence Communications in Contemporary Mathematics, 20, 8, 1850002
Publication Publié, 2018-12
Article révisé par les pairs
Résumé : We provide closed formulas for (unique) solutions of nonhomogeneous Dirichlet problems on balls involving any positive power s > 0 of the Laplacian. We are able to prescribe values outside the domain and boundary data of different orders using explicit Poisson-type kernels and a new notion of higher-order boundary operator, which recovers normal derivatives if s e N. Our results unify and generalize previous approaches in the study of polyharmonic operators and fractional Laplacians. As applications, we show a novel characterization of s-harmonic functions in terms of Martin kernels, a higher-order fractional Hopf Lemma, and examples of positive and sign-changing Green functions.