On a fractional boundary version of Talenti's inequality in the unit ball
arXiv:2411.14534 · doi:10.1016/j.nonrwa.2025.104482
Abstract
Inspired by recent work of Ferone and Volzone arXiv:2007.13195, we derive sufficient conditions for the validity and non-validity of a boundary version of Talenti's comparison principle in the context of Dirichlet-Poisson problems for the fractional Laplacian in the unit ball . In particular, our results imply a universial failure of the classical pointwise Talenti inequality in the fractional radial context which sheds new light on the one-dimensional counterexamples given in arXiv:2007.13195.