2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/77453We review the literature concerning the Hardy inequality for regions in Euclidean space and in manifolds, concentrating on the best constants. We also give applications of these inequalities to boundary decay and spectral approximation.To appear in the Proceedings of the Conference in Rostock, Sept 1998, in honour of V G Maz'yaSpectral TheoryMathematical Physics35P99;35P20;47A75;47B25text