Maria J. Esteban, Michael Loss Self-adjointness for Dirac operators via Hardy-Dirac inequalities (330K, Postscript) ABSTRACT. Distinguished selfadjoint extension of Dirac operators are constructed for a class of potentials including Coulombic ones up to the critical case, $-|x|^{-1}$. The method uses Hardy-Dirac inequalities and quadratic form techniques.