The Gauss map of Minimal graphs in the Heisenberg group
  In this paper we study some geometric properties of surfaces in the Heisenberg group, $\mathcal{H}_{3}.$ We obtain, using the Gauss map for Lie groups, a partial classification of minimal graphs in $\mathcal{H}_{3}.$ We also proof the non existence of umbilical surfaces in $\mathcal{H}_{3}.$ 
Christiam Figueroa
math.DG