Compact holomorphically pseudosymmetric Kähler manifolds
The aim of this paper is to present the first examples of compact, simply connected holomorphically pseudosymmetric Kähler manifolds.
Compact Kähler-Einstein Surfaces of Nonpositive Bisectional Curvature.
Compact manifolds with exceptional holonomy.
Compact Riemannian manifolds with homogeneous geodesics.
Compactifications kähleriennes de voisinages ouverts de cycles géométriquement positifs
Complete Riemannian manifolds admitting a pair of Einstein-Weyl structures
We prove that a connected Riemannian manifold admitting a pair of non-trivial Einstein-Weyl structures with constant scalar curvature is either Einstein, or the dual field of is Killing. Next, let be a complete and connected Riemannian manifold of dimension at least admitting a pair of Einstein-Weyl structures . Then the Einstein-Weyl vector field (dual to the -form ) generates an infinitesimal harmonic transformation if and only if is Killing.
Complex Contact Structures and the First Eigenvalue of the Dirac Operator on Kähler Manifolds.
Conformal and related changes of metric on the product of two almost contact metric manifolds.
This paper studies conformal and related changes of the product metric on the product of two almost contact metric manifolds. It is shown that if one factor is Sasakian, the other is not, but that locally the second factor is of the type studied by Kenmotsu. The results are more general and given in terms of trans-Sasakian, α-Sasakian and β-Kenmotsu structures.
Conformal Dirichlet-Neumann maps and Poincaré-Einstein manifolds.
Conformal Ricci Soliton in Lorentzian -Sasakian Manifolds
In this paper we have studied conformal curvature tensor, conharmonic curvature tensor, projective curvature tensor in Lorentzian -Sasakian manifolds admitting conformal Ricci soliton. We have found that a Weyl conformally semi symmetric Lorentzian -Sasakian manifold admitting conformal Ricci soliton is -Einstein manifold. We have also studied conharmonically Ricci symmetric Lorentzian -Sasakian manifold admitting conformal Ricci soliton. Similarly we have proved that a Lorentzian -Sasakian...
Conformally flat contact metric manifolds with .
Conformally flat Lorentzian three-spaces with various properties of symmetry and homogeneity
We study conformally flat Lorentzian three-manifolds which are either semi-symmetric or pseudo-symmetric. Their complete classification is obtained under hypotheses of local homogeneity and curvature homogeneity. Moreover, examples which are not curvature homogeneous are described.
Conformally flat manifolds, Kleinian groups and scalar curvature.
Conformally flat pseudo-symmetric spaces of constant type
We give the complete classification of conformally flat pseudo-symmetric spaces of constant type.
Conformally flat semi-symmetric spaces
We obtain the complete classification of conformally flat semi-symmetric spaces.
Constancy of maps into -manifolds and pseudo -manifolds.
Constant Jacobi osculating rank of
In this paper we obtain an interesting relation between the covariant derivatives of the Jacobi operator valid for all geodesic on the flag manifold . As a consequence, an explicit expression of the Jacobi operator independent of the geodesic can be obtained on such a manifold. Moreover, we show the way to calculate the Jacobi vector fields on this manifold by a new formula valid on every g.o. space.
Construction de métriques d’Einstein à partir de transformations biconformes
L’objectif de cet article est de proposer une nouvelle méthode de construction de métriques d’Einstein. Le procédé consiste à considérer un morphisme harmonique ; on déforme ensuite biconformément la métrique en , en conservant l’harmonicité, ce qui simplifie le calcul de la courbure de Ricci. L’équation se traduit alors en un système différentiel en termes des paramètres de la déformation. On montre d’abord l’existence de solutions par un procédé dynamique. Puis, on résout ce système dans...
Construction of Einstein metrics by generalized Dehn filling
In this paper, we present a new approach to the construction of Einstein metrics by a generalization of Thurston's Dehn filling. In particular in dimension 3, we will obtain an analytic proof of Thurston's result.
Contact co-isotropic CR submanifolds of a pseudo-Sasakian manifold.