Subordination and superordination results for -like functions.
In questa Nota diamo una caratterizzazione dell'insieme di tutti i flocks lineari della quadrica iperbolica assolutamente irriducibile in .
A problem of finding a system of proportionally located parallel supporting hyperplanes of a family of connected compact sets is analyzed. A special attention is paid to finding a common supporting halfspace. An existence theorem is proved and a method of solution is proposed.
The aim of this paper is to give a classification of the right-angled hyperbolic hexagons in the real hyperbolic space , by using a quaternionic distance between geodesics in .
Un polyèdre hyperbolique semi-idéal est un polyèdre dont les sommets sont dans l’espace hyperbolique ou à l’infini. Un polyèdre hyperbolique hyperidéal est, dans le modèle projectif, l’intersection de avec un polyèdre projectif dont les sommets sont tous en dehors de et dont toutes les arêtes rencontrent . Nous classifions les polyèdres semi-idéaux en fonction de leur métrique duale, d’après les résultats de Rivin dans [8] (écrit avec C.D.Hodgson) et [7]. Nous utilisons ce résultat pour retrouver...
The theorem of Edmonds and Fulkerson states that the partial transversals of a finite family of sets form a matroid. The aim of this paper is to present a symmetrized and continuous generalization of this theorem.
In 1994, Sturmfels gave a polyhedral version of the Cayley Trick of elimination theory: he established an order-preserving bijection between the posets of coherent mixed subdivisions of a Minkowski sum of point configurations and of coherent polyhedral subdivisions of the associated Cayley embedding . In this paper we extend this correspondence in a natural way to cover also non-coherent subdivisions. As an application, we show that the Cayley Trick combined with results of Santos on subdivisions...