International Journal of Mathematics and Mathematical Sciences
Volume 2003 (2003), Issue 35, Pages 2203-2220
doi:10.1155/S0161171203212370
Hausdorff measure of the singular set of quasiregular maps on Carnot groups
Departamento de Matemática, Universidad Técnica Federico Santa María, Casilla 110-V, Valparaíso, Chile
Received 14 December 2002
Copyright © 2003 Irina Markina. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
Recently, the theory of quasiregular mappings on Carnot groups has been developed intensively. Let ν stand for the homogeneous dimension of a Carnot group and let m be the index of the last vector space of the corresponding Lie algebra. We prove that the (ν−m−1)-dimensional Hausdorff measure of the image of the branch set of a quasiregular mapping on the Carnot group is positive. Some estimates of the local index of quasiregular mappings are also obtained.