The Bernstein problem for (X, Y)-Lipschitz surfaces in three-dimensional sub-Finsler Heisenberg groups.

In the Heisenberg group H1 with a sub-Finsler structure, an (X, Y)-Lipschitz surface which is complete, oriented, connected and stable must be a vertical plane. In particular, the result holds for entire intrinsic graphs of Euclidean Lipschitz functions. [ABSTRACT FROM AUTHOR]