2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/73593We establish sharp regularity and Fredholm theorems for the \bar{\partial}_b-Neumann problem on domains satisfying some non-generic geometric conditions. We use these domains to construct explicit examples of bad behaviour of the Kohn Laplacian: it is not always hypoelliptic up to the boundary, its partial inverse is not compact and it is not globally subelliptic.38 pagesComplex VariablesDifferential Geometry32W10 (primary); 32V20; 35H20 (secondary)text