Lifts of Lipschitz maps and horizontal fractals in the Heisenberg group

Zoltán M. Balogh, Regula Hoefer-Isenegger, Jeremy T. Tyson

Research output: Contribution to journalArticlepeer-review


We consider horizontal iterated function systems in the Heisenberg group ℍ1, i.e. collections of Lipschitz contractions of ℍ1 with respect to the Heisenberg metric. The invariant sets for such systems are so-called horizontal fractals. We study questions related to connectivity of horizontal fractals and regularity of functions whose graph lies within a horizontal fractal. Our construction yields examples of horizontal BV (bounded variation) surfaces in ℍ1 that are in contrast with the non-existence of horizontal Lipschitz surfaces which was recently proved by Ambrosio and Kirchheim (Rectifiable sets in metric and Banach spaces. Math. Ann. 318(3) (2000), 527-555).

Original languageEnglish (US)
Pages (from-to)621-651
Number of pages31
JournalErgodic Theory and Dynamical Systems
Issue number3
StatePublished - Jun 2006

ASJC Scopus subject areas

  • General Mathematics
  • Applied Mathematics


Dive into the research topics of 'Lifts of Lipschitz maps and horizontal fractals in the Heisenberg group'. Together they form a unique fingerprint.

Cite this