(..., ...)-and (..., ...)-connexions of an almost complex and an almost product space.
1 Structure de contact et équations aux dérivées partielles d'après V. V. Lychagin
3 Classification des plongements isotropes d'après A. Weinstein
3-submersions from QR-hypersurfaces of quaternionic Kähler manifolds
We study 3-submersions from a QR-hypersurface of a quaternionic Kähler manifold onto an almost quaternionic hermitian manifold. We also prove the non-existence of quaternionic submersions between quaternionic Kähler manifolds which are not locally hyper-Kähler.
4 Feuilletages et mécanique hamiltonienne
A basic inequality for submanifolds in a cosymplectic space form.
A boundary rigidity problem for holomorphic mappings.
A characterization of tangent and stable tangent bundles
A class of 3-dimensional almost Kenmotsu manifolds with harmonic curvature tensors
Let M3 be a three-dimensional almost Kenmotsu manifold satisfying ▽ξh = 0. In this paper, we prove that the curvature tensor of M3 is harmonic if and only if M3 is locally isometric to either the hyperbolic space ℍ3(-1) or the Riemannian product ℍ2(−4) × ℝ. This generalizes a recent result obtained by [Wang Y., Three-dimensional locally symmetric almost Kenmotsu manifolds, Ann. Polon. Math., 2016, 116, 79-86] and [Cho J.T., Local symmetry on almost Kenmotsu three-manifolds, Hokkaido Math. J., 2016,...
A class of locally symmetric Kähler Einstein structures on the nonzero cotangent bundle of a space form.
A Class of Non-Polarizable Symplectic Manifolds.
A classification of certain submanifolds of an S-manifold
A classification theorem is obtained for submanifolds with parallel second fundamental form of an 𝑆-manifold whose invariant f-sectional curvature is constant.
A classification of contact metric 3-manifolds with constant -sectional and -sectional curvatures.
A classification of Monge-Ampère equations
A collar neighborhood theorem for a complex manifold
A complete classification of four-dimensional paraKähler Lie algebras
We consider paraKähler Lie algebras, that is, even-dimensional Lie algebras g equipped with a pair (J, g), where J is a paracomplex structure and g a pseudo-Riemannian metric, such that the fundamental 2-form Ω(X, Y) = g(X, JY) is symplectic. A complete classification is obtained in dimension four.
A connection in a differential module
A contact metric manifold satisfying a certain curvature condition
In the present paper we investigate a contact metric manifold satisfying (C) for any -geodesic , where is the Tanaka connection. We classify the 3-dimensional contact metric manifolds satisfying (C) for any -geodesic . Also, we prove a structure theorem for a contact metric manifold with belonging to the -nullity distribution and satisfying (C) for any -geodesic .
A convex Darboux theorem
A Direct Extension Method for CR Structures.