Abstract
We show the existence of a non-injective uniformly quasiregular mapping acting on the one-point compactification \(\bar{ {\mathbb{H}}}^{1}={\mathbb{H}}^{1}\cup\{\infty\}\) of the Heisenberg group ℍ1 equipped with a sub-Riemannian metric. The corresponding statement for arbitrary quasiregular mappings acting on sphere \({\mathbb{S}}^{n} \) was proven by Martin (Conform. Geom. Dyn. 1:24–27, 1997). Moreover, we construct uniformly quasiregular mappings on \(\bar{ {\mathbb{H}}}^{1}\) with large-dimensional branch sets. We prove that for any uniformly quasiregular map g on \(\bar{ {\mathbb{H}}}^{1}\) there exists a measurable CR structure μ which is equivariant under the semigroup Γ generated by g. This is equivalent to the existence of an equivariant horizontal conformal structure.
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Astala, K., Iwaniec, T., Martin, G.: Elliptic Partial Differential Equations and Quasiconformal Mappings in the Plane. Princeton Mathematical Series, vol. 48. Princeton University Press, Princeton (2009)
Astola, L., Kangaslampi, R., Peltonen, K.: Lattès type mappings on compact manifolds. Conform. Geom. Dyn. (2009, accepted for publication)
Balogh, Z.M.: Hausdorff dimension distribution of quasiconformal mappings on the Heisenberg group. J. Anal. Math. 83, 289–312 (2001)
Balogh, Z.M., Koskela, P.: Quasiconformality, quasisymmetry and removability in Loewner spaces. Duke Math. J. 101, 555–572 (2000)
Capogna, L.: Regularity of quasi-linear equations in the Heisenberg group. Commun. Pure Appl. Math. 50(9), 867–889 (1997)
Dairbekov, N.S.: Mappings with bounded distortion on Heisenberg groups. Sib. Mat. Zh. 41(3), 567–590 (2000)
Dairbekov, N.S.: Mappings with bounded distortion on two-step Carnot groups. In: Proceedings on Analysis and Geometry, Russian Novosibirsk Akademgorodok, 1999, pp. 122–155. Izdat. Ross. Akad. Nauk Sib. Otd. Inst. Mat., Novosibirsk (2000)
Dragomir, S., Tomassini, G.: Differential Geometry and Analysis on CR Manifolds. Progress in Mathematics, vol. 246. Birkhäuser Boston, Boston (2006)
Forstnerič, F.: Extending proper holomorphic mappings of positive codimension. Invent. Math. 95(1), 31–61 (1989)
Gromov, M.: Carnot-Carathéodory spaces seen from within. In: Sub-Riemannian Geometry. Progress in Mathematics, vol. 144, Birkhäuser, Basel (1996)
Heinonen, J.: Calculus on Carnot groups. In: Fall School in Analysis, Jyväskylä, 1994. Report, vol. 68, pp. 1–31. Univ. Jyväskylä, Jyväskylä (1995)
Heinonen, J.: Lectures on Analysis on Metric Spaces. Springer, New York (2001)
Heinonen, J., Holopainen, I.: Quasiregular maps on Carnot groups. J. Geom. Anal. 7(1), 109–148 (1997)
Heinonen, J., Koskela, P.: Quasiconformal maps in metric spaces with controlled geometry. Acta Math. 181, 1–61 (1998)
Heinonen, J., Semmes, S.: Thirty-three yes or no questions about mappings, measures, and metrics. Conform. Geom. Dyn. 1, 1–12 (1997) (electronic)
Hinkkanen, A.: Uniformly quasiregular semigroups in two dimensions. Ann. Acad. Sci. Fenn. Math. 21(1), 205–222 (1996)
Holopainen, I., Rickman, S.: Quasiregular mappings of the Heisenberg group. Math. Ann. 294(4), 625–643 (1992)
Iwaniec, T., Martin, G.: Quasiregular semigroups. Ann. Acad. Sci. Fenn. Math. 21(2), 241–254 (1996)
Iwaniec, T., Martin, G.: Geometric Function Theory and Non-Linear Analysis. Oxford Mathematical Monographs. Clarendon/Oxford University Press, New York (2001)
Korányi, A.: Geometric properties of Heisenberg-type groups. Adv. Math. 56(1), 28–38 (1985)
Korányi, A., Reimann, H.M.: Quasiconformal mappings on the Heisenberg group. Invent. Math. 80(2), 309–338 (1985)
Korányi, A., Reimann, H.M.: Quasiconformal mappings on CR manifolds. In: Complex Geometry and Analysis, Pisa, 1988. Lecture Notes in Math, vol. 1422, pp. 59–75. Springer, Berlin (1990)
Korányi, A., Reimann, H.M.: Foundations for the theory of quasiconformal mappings on the Heisenberg group. Adv. Math. 111(1), 1–87 (1995)
Markina, I.: Hausdorff measure of the singular set of quasiregular maps on Carnot groups. Int. J. Math. Math. Sci. 35, 2203–2220 (2003)
Markina, I., Vodopyanov, S.: On value distributions for quasimeromorphic mappings on \(\Bbb{H}\)-type Carnot groups. Bull. Sci. Math. 130(6), 467–523 (2006)
Martin, G.J.: Branch sets of uniformly quasiregular maps. Conform. Geom. Dyn. 1, 24–27 (1997) (electronic)
Martin, G., Peltonen, K.: Stoïlow factorization for quasiregular mappings in all dimensions. Proc. Am. Math. Soc. 138, 147–151 (2010)
Mayer, V.: Uniformly quasiregular mappings of Lattès type. Conform. Geom. Dyn. 1, 104–111 (1997) (electronic)
Peltonen, K.: Examples of uniformly quasiregular mappings. Conform. Geom. Dyn. 3, 158–163 (1999) (electronic)
Poincaré, H.: Les fonctions analytiques de deux variables et la représentation conforme. Rend. Circ. Mat. Palermo II(23), 185–220 (1907)
Rickman, S.: Quasiregular Mappings. Ergebnisse der Mathematik und ihrer Grenzgebiete (3) [Results in Mathematics and Related Areas (3)], vol. 26. Springer, Berlin (1993)
Tanaka, N.: On the pseudo-conformal geometry of hypersurfaces of the space of n complex variables. J. Math. Soc. Jpn. 14, 397–429 (1962)
Tang, P.: Quasiconformal homeomorphisms on CR 3-manifolds with symmetries. Math. Z. 219(1), 49–69 (1995)
Tang, P.: Regularity and extremality of quasiconformal homeomorphisms on CR 3-manifolds. Ann. Acad. Sci. Fenn. Math. 21(2), 289–308 (1996)
Tukia, P.: On two-dimensional quasiconformal groups. Ann. Acad. Sci. Fenn., Ser. A 1 Math. 5(1), 73–78 (1980)
Tukia, P., Väisälä, J.: Lipschitz and quasiconformal approximation and extension. Ann. Acad. Sci. Fenn., Ser. A 1 Math. 6(2), 303–342 (1982)
Vodop’yanov, S.K.: Mappings with bounded distortion and with finite distortion on Carnot groups. Sib. Mat. Zh. 40(4), 764–804 (1999)
Walter, W.: Ordinary Differential Equations. Graduate Texts in Mathematics, vol. 182. Springer, New York (1998). Translated from the sixth German (1996) edition by Russell Thompson, Readings in Mathematics
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Communicated by Fulvio Ricci.
The authors were supported by Swiss National Science Foundation, European Research Council Project GALA and European Science Foundation Project HCAA.
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Balogh, Z.M., Fässler, K. & Peltonen, K. Uniformly Quasiregular Maps on the Compactified Heisenberg Group. J Geom Anal 22, 633–665 (2012). https://doi.org/10.1007/s12220-010-9205-5
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DOI: https://doi.org/10.1007/s12220-010-9205-5