Curvature tensor of pseudo metric semi-symmetric connexions in an almost contact metric manifold.
Curvature tensors and Ricci solitons with respect to Zamkovoy connection in anti-invariant submanifolds of trans-Sasakian manifold
The present paper deals with the study of some properties of anti-invariant submanifolds of trans-Sasakian manifold with respect to a new non-metric affine connection called Zamkovoy connection. The nature of Ricci flat, concircularly flat, -projectively flat, -projectively flat, --projectively flat, pseudo projectively flat and -pseudo projectively flat anti-invariant submanifolds of trans-Sasakian manifold admitting Zamkovoy connection are discussed. Moreover, Ricci solitons on Ricci flat,...
Curvature tensors and Singer invariants of four-dimensional homogeneous spaces
We show that the Singer invariant of a four-dimensional homogeneous space is at most .
Curvature tensors in dimension four which do not belong to any curvature homogeneous space
A six-parameter family is constructed of (algebraic) Riemannian curvature tensors in dimension four which do not belong to any curvature homogeneous space. Also a general method is given for a possible extension of this result.
Curvature tensors of complex and double-quadratic elliptic spaces.
Curvature tensors on -Einstein Sasakian manifolds.
Curvature testing in 3-dimensional metric polyhedral complexes.
Curvature-decreasing maps are volume-decreasing. On joint work with G. Besson and G. Courtois.
Curvatures of the diagonal lift from an affine manifold to the linear frame bundle
We investigate the curvature of the so-called diagonal lift from an affine manifold to the linear frame bundle LM. This is an affine analogue (but not a direct generalization) of the Sasaki-Mok metric on LM investigated by L.A. Cordero and M. de León in 1986. The Sasaki-Mok metric is constructed over a Riemannian manifold as base manifold. We receive analogous and, surprisingly, even stronger results in our affine setting.
Curve shortening flow and the Banchoff-Pohl inequality on surfaces of nonpositive curvature.
Curve shortening on surfaces
Curved Casimir operators and the BGG machinery.
Curved flats in symmetric spaces.
Curves in Lorentzian spaces
The notion of ``hyperbolic'' angle between any two time-like directions in the Lorentzian plane was properly defined and studied by Birman and Nomizu [1,2]. In this article, we define the notion of hyperbolic angle between any two non-null directions in and we define a measure on the set of these hyperbolic angles. As an application, we extend Scofield's work on the Euclidean curves of constant precession [9] to the Lorentzian setting, thus expliciting space-like curves in whose natural equations...
Curves in P² and symplectic packings.
Curves of minimal order.
Cusp closing in rank one symmetric spaces.
Cut and singular loci up to codimension 3
We give a new and detailed description of the structure of cut loci, with direct applications to the singular sets of some Hamilton-Jacobi equations. These sets may be non-triangulable, but a local description at all points except for a set of Hausdorff dimension is well known. We go further in this direction by giving a classification of all points up to a set of Hausdorff dimension .
Cut loci of closed surfaces without conjugate points
Cut locus and optimal synthesis in the sub-Riemannian problem on the group of motions of a plane*
The left-invariant sub-Riemannian problem on the group of motions (rototranslations) of a plane SE(2) is considered. In the previous works [Moiseev and Sachkov, ESAIM: COCV, DOI: 10.1051/cocv/2009004; Sachkov, ESAIM: COCV, DOI: 10.1051/cocv/2009031], extremal trajectories were defined, their local and global optimality were studied. In this paper the global structure of the exponential mapping is described. On this basis an explicit characterization of the cut locus and Maxwell set is obtained....