Resumen de Regular submanifolds, graphs and area formula in Heisenberg groups
B. Franchi, Raul Serapioni, Francesco Serra Cassano
We describe intrinsically regular submanifolds in Heisenberg groups H. Low dimensional and low codimensional submanifolds turn out to be of a very different nature. The first ones are Legendrian surfaces, while low codimensional ones are more general objects, possibly non-Euclidean rectifiable. Nevertheless we prove that they are graphs in a natural group way, as well as that an area formula holds for the intrinsic Hausdorff measure. Finally, they can be seen as Federer¿Fleming currents given a natural complex of differential forms on H
