Simply-connected minimal surfaces with finite total curvature in H²timesR

Laurent Hauswirth and Harold Rosenberg developed the theory of minimal surfaces with finite total curvature in $\H^2\times\R$. They showed that the total curvature of one such a surface must be a non-negative integer multiple of $-2\pi$. The first examples appearing in this context are vertical geodesic planes and Scherk minimal graphs over ideal polygonal domains. Other non simply-connected examples have been constructed recently. In the present paper, we show that the only complete minimal surfaces in $\H^2\times\R$ of total curvature $-2\pi$ are Scherk minimal graphs over ideal quadrilaterals. We also construct properly embedded simply-connected minimal surfaces with total curvature $-4k\pi$, for any integer $k\geq 1$, which are not Scherk minimal graphs over ideal polygonal domains.