Completeness of projective special K\"ahler and quaternionic K\"ahler manifolds

We prove that every projective special K"ahler manifold with \emph{regular boundary behaviour} is complete and defines a family of complete quaternionic K"ahler manifolds depending on a parameter $c\ge 0$. We also show that, irrespective of its boundary behaviour, every complete projective special K"ahler manifold with \emph{cubic prepotential} gives rise to such a family. Examples include non-trivial deformations of non-compact symmetric quaternionic K"ahler manifolds.