This paper presents a new and efficient algorithm for the decomposition of 3D arbitrary triangle meshes and particularly optimized triangulated CAD meshes. The algorithm is based on the curvature tensor field analysis and presents two distinct complementary steps: a region based segmentation, which is an improvement of that presented by Lavoue et al. [Lavoue G, Dupont F, Baskurt A. Constant cur...

Let M be a differentiable manifold. We say that a tensor field g defined on M is non-regular if g is in some local L space or if g is continuous. In this work we define a mollifier smoothing gε of g that has the following feature: If g is a Riemannian metric of class C, then the Levi-Civita connection and the Riemannian curvature tensor of gε converges to the Levi-Civita connection and to the R...

Classical general relativity from quantum gravity and the generalized Kodama states. Abstract In this paper we investigate the relation between the CDJ matrix used for construction of the generalized Kodama states and the Weyl curvature tensor. By exploiting special self-duality relations unique to four dimensional spacetime, we show that the effects of quantum gravity in Ashtekar variables are...

We present a gauge-invariant formalism to study the evolution of the curvature and entropy perturbations in the case in which spatial and time variations of the inflaton decay rate into ordinary matter are present. During the reheating stage after inflation curvature perturbations can vary with time on super-horizon scales sourced by a a gauge-invariant inflaton decay rate perturbation. We show...

For compact Kählerian manifolds, the holomorphic pseudosymmetry reduces to the local symmetry if additionally the scalar curvature is constant and the structure function is non-negative. Similarly, the holomorphic Ricci-pseudosymmetry reduces to the Ricci-symmetry under these additional assumptions. We construct examples of non-compact essentially holomorphically pseudosymmetric Kählerian manif...

Accurate estimations of geometric properties of a surface from its discrete approximation are important for many computer graphics and geometric modeling applications. Especially, curvature estimation of a mesh is an active research area [GI04, CSM03, CP03] with many applications. The most important curvature measures on a surface are the mean curvature H, the Gaussian curvature K, and the curv...

In this paper, we study certain curvature conditions satisfying by the conharmonic curvature tensor in a Lorentzian para-Sasakian manifold with respect to the quarter-symmetric metric connection. AMS Mathematics Subject Classification (2010): 53B05, 53C25

it is easily seen that a motion and a homothetic transformation are both affine collineations and that an affine collineation preserves the curvature tensor. In [l ] one of the present authors proved that in a space of nonzero constant curvature a mapping preserving curvature is a motion. For an Einstein space with nonzero curvature scalar, a mapping preserving Ricci curvature is a motion; for ...