Sub-riemannian geometry from intrinsic viewpoint
نویسنده
چکیده
Gromov proposed to extract the (differential) geometric content of a sub-riemannian space exclusively from its Carnot-Carathéodory distance. One of the most striking features of a regular sub-riemannian space is that it has at any point a metric tangent space with the algebraic structure of a Carnot group, hence a homogeneous Lie group. Siebert characterizes homogeneous Lie groups as locally compact groups admitting a contracting and continuous one-parameter group of automorphisms. Siebert result has not a metric character. In these notes I show that sub-riemannian geometry may be described by about 12 axioms, without using any a priori given differential structure, but using dilation structures instead. Dilation structures bring forth the other intrinsic ingredient, namely the dilations, thus blending Gromov metric point of view with Siebert algebraic one. MSC2000: 51K10, 53C17, 53C23
منابع مشابه
Dilatation structures in sub-riemannian geometry
Based on the notion of dilatation structure [2], we give an intrinsic treatment to sub-riemannian geometry, started in the paper [4]. Here we prove that regular sub-riemannian manifolds admit dilatation structures. From the existence of normal frames proved by Belläıche we deduce the rest of the properties of regular sub-riemannian manifolds by using the formalism of dilatation structures.
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