Examples of area-minimizing surfaces in the subriemannian Heisenberg   group H^1 with low regularity
  We give new examples of entire area-minimizing t-graphs in the subriemannian Heisenberg group H^1. Most of the examples are locally lipschitz in Euclidean sense. Some regular examples have prescribed singular set consisting of either a horizontal line or a finite number of horizontal halflines extending from a given point. Amongst them, a large family of area-minimizing cones is obtained. 
Manuel Ritor\'e