Symbolic approach and induction in the Heisenberg group
  We associate a homomorphism in the Heisenberg group to each hyperbolic unimodular automorphism of the free group on two generators. We show that the first return-time of some flows in "good" sections, are conjugate to niltranslations, which have the property of being self-induced. 
Jean-Fran\c{c}ois Bertazzon
math.DS