Sharp and quantitative bounds for torsional rigidity with Dirichlet and Robin boundary conditions
par
Carmes
Torsional rigidity is a classical quantity associated with the Poisson problem with
Dirichlet boundary conditions and is closely related to the geometry of the underlying
domain. In this talk we consider open, bounded and convex sets in R^n and present sharp
geometric inequalities relating torsional rigidity to basic geometric quantities such as the
perimeter, the measure of the set, and the inradius. We also discuss quantitative versions of
these inequalities, where the deficit from the optimal constant provides information on the
geometry of the optimal sequences. Finally, we address extensions of these results to
torsional rigidity with Robin boundary conditions, focusing on the case of positive Robin
parameter and highlighting the main similarities and differences with respect to the classical
Dirichlet setting.