Fenchel type theorems for submanifolds of Sn.
Dans ce travail: (1) on caractérise l’espace des fonctionnelles invariantes par un groupe compact G opérant linéairement et continûment sur un espace vectoriel topologique localement convexe séparé et séquentiellement complet E plus précisément, on montre que est le dual topologique du sous-espace des vecteurs de E qui sont G-invariants. (2) On étudie les courants basiques sur une variété feuilletée (V,ℱ). On obtient alors, dans le cas où le feuilletage est associé à une action localement...
The distributional -dimensional Jacobian of a map in the Sobolev space which takes values in the sphere can be viewed as the boundary of a rectifiable current of codimension carried by (part of) the singularity of which is topologically relevant. The main purpose of this paper is to investigate the range of the Jacobian operator; in particular, we show that any boundary of codimension can be realized as Jacobian of a Sobolev map valued in . In case is polyhedral, the map we construct...
In the first section of the paper we study some properties of oriented volumes of wave fronts propagating in spaces of constant curvature. In the second section, we generalize to an arbitrary isometric action of a Lie group on a Riemannian manifold the following principle: an extra pression inside of a ball does not move it.
Motivated by the well-posedness of birth-and-growth processes, a stochastic geometric differential equation and, hence, a stochastic geometric dynamical system are proposed. In fact, a birth-and-growth process can be rigorously modeled as a suitable combination, involving the Minkowski sum and the Aumann integral, of two very general set-valued processes representing nucleation and growth dynamics, respectively. The simplicity of the proposed geometric approach allows to avoid problems of boundary...