-metrische Zusammenhänge in isotropen Mannigfaltigkeiten. (- metric connections in isotropic manifolds).
Scalar curvature on lightlike hypersurfaces.
Schéma géométrique à tenseur impulsion-énergie asymétrique. Application à l'étude relativiste de la matière à spin
Screen transversal lightlike submanifolds of indefinite cosymplectic manifolds
Self-duality and pointwise Osserman manifolds
This paper is a contribution to the mathematical modelling of the hump effect. We present a mathematical study (existence, homogenization) of a Hamilton-Jacobi problem which represents the propagation of a front flame in a striated media.
Semigroups in the simply connected covering of SL(2).
Semi-riemannian Manifolds Whose Weyl Tensor is a Kulkarni--nomizu Square
Semi-Riemannian manifolds whose Weyl tensor is a Kulkarni-Nomizu square.
Semisymmetry and Ricci-symmetry for Hypersurfaces of Semi-euclidean Spaces
Shells of monotone curves
We determine in the form of curves corresponding to strictly monotone functions as well as the components of affine connections for which any image of under a compact-free group of affinities containing the translation group is a geodesic with respect to . Special attention is paid to the case that contains many dilatations or that is a curve in . If is a curve in and is the translation group then we calculate not only the components of the curvature and the Weyl tensor but...
Simple conformally symmetric manifolds with metric semi-symmetric connection
Singular points of lightlike hypersurfaces of the de Sitter space.
Some Additive Designs
Given a finite additive abelian group and an integer , with , denote by the simple incidence structure whose point-set is and whose blocks are the -subsets of such that . It is known (see [Caggegi, A., Di Bartolo, A., Falcone, G.: Boolean 2-designs and the embedding of a 2-design in a group arxiv 0806.3433v2, (2008), 1–8.]) that is a 2-design, if is an elementary abelian -group with a prime divisor of . From [Caggegi, A., Falcone, G., Pavone, M.: On the additivity of block...
Some characterizations of rectifying curves in the Minkowski 3-space.
Some characterizations of the spacelike, the timelike and the null curves on the pseudohyperbolic space H02 in E13
Some indefinite metrics and covariant derivatives of their curvature tensors
Some Nonsemisymmetric Ricci-semisymmetric Warped Product Hypersurfaces
Some properties of para-Kähler-Walker metrics
A Walker 4-manifold is a pseudo-Riemannian manifold (M₄,g) of neutral signature, which admits a field of parallel null 2-planes. We study almost paracomplex structures on 4-dimensional para-Kähler-Walker manifolds. In particular, we obtain conditions under which these almost paracomplex structures are integrable, and the corresponding para-Kähler forms are symplectic. We also show that Petean's example of a nonflat indefinite Kähler-Einstein 4-manifold is a special case of our constructions.
Some results on projectively flat affine surfaces
We focus our attention on projectively flat affine surfaces. First, we classify the affine surfaces with projectively flat induced connection and constant Pick invariant. We also investigate the compact case and study how the geometry at the boundary determines the geometry of the surface.
Some trigonometric relations in the Lorentzian plane