Abstract:
The sphere and front of a flat sub-Riemannian structure on the Martinet distribution are surfaces with nonisolated singularities in three-dimensional space. The sphere is a subset of the front; it is not subanalytic at two antipodal points (the poles). The asymptotic behaviour of the sub-Riemannian sphere and Martinet front are calculated at these points: each surface is approximated by a pair of quasihomogeneous surfaces with distinct sets of weights in a neighbourhood of a pole.
Bibliography: 13 titles.
Keywords:sphere of a sub-Riemannian structure, front of a sub-Riemannian structure, Martinet distribution, exponential map, Jacobi elliptic functions.