Proper homothetic vector fields in Bianchi type-I space-time.
Properties of a hypothetical exotic complex structure on
We consider almost-complex structures on whose total Chern classes differ from that of the standard (integrable) almost-complex structure. E. Thomas established the existence of many such structures. We show that if there exists an “exotic” integrable almost-complex structures, then the resulting complex manifold would have specific Hodge numbers which do not vanish. We also give a necessary condition for the nondegeneration of the Frölicher spectral sequence at the second level.
Properties of complete non-compact Kähler surfaces of negative Ricci curvature.
Properties of Conflict Sets in the Plane
This paper studies the smoothness and the curvature of conflict sets of the distance function in the plane. Conflict sets are also well known as 'bisectors'. We prove smoothness in the case of two convex sets and give a formula for the curvature. We generalize moreover to weighted distance functions, the so-called Johnson-Mehl model.
Properties of distance functions on convex surfaces and applications
If is a convex surface in a Euclidean space, then the squared intrinsic distance function is DC (d.c., delta-convex) on in the only natural extrinsic sense. An analogous result holds for the squared distance function from a closed set . Applications concerning -boundaries (distance spheres) and ambiguous loci (exoskeletons) of closed subsets of a convex surface are given.
Properties of hypersurfaces which are characteristic for spaces of constant curvature
Properties of Kählerian twistor-spinors and vanishing theorems.
Properties of operators occurring in the Penrose transform
It is shown that operators occurring in the classical Penrose transform are differential. These operators are identified depending on line bundles over the twistor space.
Properties of product preserving functors
A product preserving functor is a covariant functor from the category of all manifolds and smooth mappings into the category of fibered manifolds satisfying a list of axioms the main of which is product preserving: . It is known that any product preserving functor is equivalent to a Weil functor . Here is the set of equivalence classes of smooth maps and are equivalent if and only if for every smooth function the formal Taylor series at 0 of and are equal in . In this paper all...
Properties of Pseudo-holomorphic Curves in Symplectisations II: Embedding Controls and Algebraic Invariants.
Properties of pseudoholomorphic curves in symplectisations. I : asymptotics
Properties of space motions with two straight trajectories
The paper is devoted to Euclidean space motions with two straight trajectories on two given skew straight lines. It describes all motions from this class which have one more planar trajectory in a plane not parallel to the given lines. In the conclusion it given conditions under which such motions have further planar trajectories in planes not parallel to the given skew straight lines.
Propriété caractéristique de la droite rectifiante
Propriétés de Lefschetz dans la cohomologie de certaines variétés arithmétiques : le cas des surfaces modulaires de Hilbert
Propriétés de mélange du flot des chambres de Weyl des groupes de Ping-Pong
Dans cet article, nous étudions le flot des chambres de Weyl d’une large classe de sous-groupe discrets d’un groupe de Lie semi-simple réel : les groupes de Ping-Pong. Nous montrons que ce flot est mélangeant relativement à la mesure de Patterson-Sullivan ; celle-ci étant infinie en rang , nous précisons cette propriété de mélange en explicitant sa vitesse dans le direction du vecteur de croissance du groupe.
Propriétés ergodiques, en mesure infinie, de certains systèmes dynamiques fibrés
Propriétés génériques des fonctions propres et multiplicité.
Propriétés globales de l'espace de twisteurs
We study global properties of the twistor space over an even dimensional conformally flat manifold, proving that the twistor space is Kähler if and only if the manifold is conformally equivalent to the standard -dimensional sphere ().
Propriétés projectives des espaces symétriques affines
On donne une description algébrique de l’ensemble des classes d’isomorphisme d’espaces symétriques affines connexes, simplement connexes et projectivement plats. On en déduit une classification des espaces symétriques affines connexes et projectivement plats et on détermine tous les espaces symétriques affines connexes admettant une transformation projective non affine.
Propriétés projectives du contact. III