@misc{10481/66666, year = {2017}, month = {9}, url = {http://hdl.handle.net/10481/66666}, abstract = {In the present paper we consider the Carnot–Carathéodory distance δE to a closed set E in the sub-RiemannianHeisenberg groupsℍn, n ⩾ 1. Theℍ-regularity of δE is proved under mild conditions involving a general notion of singular points. In case E is a Euclidean Ck submanifold, k ⩾ 2, we prove that δE is Ck out of the singular set. Explicit expressions for the volume of the tubular neighborhood when the boundary of E is of class C2 are obtained, out of the singular set, in terms of the horizontal principal curvatures of ∂E and of the function ⟨N, T⟩/|Nh| and its tangent derivatives.}, organization = {European Union (EU) Spanish Government MTM2007-61919 MTM2013-48371-C2-1-P}, organization = {Junta de Andalucía FQM-325}, publisher = {Walter De Gruyter Gmbh}, keywords = {Heisenberg group}, keywords = {Carnot–Carathéodory distance}, keywords = {tubular neighborhoods}, keywords = {Distance function}, keywords = {Singular set}, keywords = {Steiner’s formula}, title = {Tubular neighborhoods in the sub-Riemannian Heisenberg groups}, doi = {10.1515/acv-2017-0011}, author = {Ritoré Cortés, Manuel María}, }