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The principal properties of geodesic normal coordinates are the vanishing of the connection components and first derivatives of the metric components at some point. It is well-known that these hold only at points where the connection has…

General Relativity and Quantum Cosmology · Physics 2010-04-06 David Hartley

The "metric" structure of nonrelativistic spacetimes consists of a one-form (the absolute clock) whose kernel is endowed with a positive-definite metric. Contrarily to the relativistic case, the metric structure and the torsion do not…

High Energy Physics - Theory · Physics 2016-02-19 Xavier Bekaert , Kevin Morand

It is shown that in every dimension n=3j+2, j=1,2,3,..., there exist compact pseudo-Riemannian manifolds with parallel Weyl tensor, which are Ricci-recurrent, but neither conformally flat nor locally symmetric, and represent all indefinite…

Differential Geometry · Mathematics 2009-12-16 Andrzej Derdzinski , Witold Roter

In this article, we examine the behavior of the Riemannian and Hermitian curvature tensors of a Hermitian metric, when one of the curvature tensors obeys all the symmetry conditions of the curvature tensor of a K\"ahler metric. We will call…

Differential Geometry · Mathematics 2023-03-31 Bo Yang , Fangyang Zheng

A natural connection with torsion is defined and it is called the first natural connection on Riemannian $\Pi$-manifold. Relations between the introduced connection and the Levi-Civita connection are obtained, as well as relations between…

Differential Geometry · Mathematics 2023-01-30 Hristo Manev

We consider a 3-dimensional Riemannian manifold V with a metric g and an affinor structure q. The local coordinates of these tensors are circulant matrices. In V we define an almost conformal transformation. Using that definition we…

Differential Geometry · Mathematics 2011-06-15 Georgi Dzhelepov , Dimitar Razpopov , Iva Dokuzova

We study the Riemann curvature tensor of (\kappa,\mu,\nu)-contact metric manifolds, which we prove to be completely determined in dimension 3, and we observe how it is affected by D_a-homothetic deformations. This prompts the definition and…

Differential Geometry · Mathematics 2015-07-28 Kadri Arslan , Alfonso Carriazo , Verónica Martín-Molina , Cengizhan Murathan

We study the geometry of the canonical connection on a quasi-Kaehler manifold with Norden metric. We consider the cases when the canonical connection has Kaehler curvature tensor and parallel torsion, and derive conditions for an…

Differential Geometry · Mathematics 2011-01-24 Dimitar Mekerov

The vector space of the tensors $\mathcal F$ of type (0,3) having the same symmetries as the covariant derivative of the fundamental form of an almost contact metric manifold is considered. A scheme of decomposition of $\mathcal F$ into…

Differential Geometry · Mathematics 2011-10-20 Valentin A. Alexiev , Georgi T. Ganchev

To any metric spaces there is an associated metric profile. The rectifiability of the metric profile gives a good notion of curvature of a sub-Riemannian space. We shall say that a curvature class is the rectifiability class of the metric…

Metric Geometry · Mathematics 2007-05-23 Marius Buliga

Connections compatible with degenerate metric structures are known to possess peculiar features: on the one hand, the compatibility conditions involve restrictions on the torsion; on the other hand, torsionfree compatible connections are…

High Energy Physics - Theory · Physics 2018-12-03 Xavier Bekaert , Kevin Morand

Finsler metrics are direct generalizations of Riemannian metrics such that the quadratic Riemannian indicatrices in the tangent spaces of a manifold are replaced by more general convex bodies as unit spheres. A linear connection on the base…

Differential Geometry · Mathematics 2022-04-05 Csaba Vincze , Márk Oláh

This paper is devoted to a systematic study and classification of invariant affine or metric connections on certain classes of naturally reductive spaces. For any non-symmetric, effective, strongly isotropy irreducible homogeneous…

Differential Geometry · Mathematics 2019-11-27 Ioannis Chrysikos , Christian O'Cadiz Gustad , Henrik Winther

Any Spin(7)-manifold admits a metric connection \nabla^c with totally skew-symmetric torsion T^c preserving the underlying structure. We classify those with \nabla^c-parallel T^c\neq0 and non-Abelian isotropy algebra iso(T^c)<spin(7). These…

Differential Geometry · Mathematics 2010-07-21 Christof Puhle

In spin geometry, traceless cyclic homogeneous Riemannian manifolds equipped with a homogeneous spin structure can be viewed as the simplest manifolds after Riemannian symmetric spin spaces. In this paper, we give some characterizations and…

Differential Geometry · Mathematics 2015-04-30 P. M. Gadea , José Carmelo González-Dávila , José A. Oubiña

The present study initially identified the generalized symmetric connections $(\alpha,\beta)$ typed, which can be regarded as more generalised forms of quarter and semi-symmetric connections. The quarter and semi-symmetric connections are…

Differential Geometry · Mathematics 2020-10-02 Mohammed Ali Alghamdi , Oğuzhan Bahadır

On Hermitian manifolds, the second Ricci curvature tensors of various metric connections are closely related to the geometry of Hermitian manifolds. By refining the Bochner formulas for any Hermitian complex vector bundle (Riemannain real…

Differential Geometry · Mathematics 2010-11-16 Kefeng Liu , Xiaokui Yang

The paper is devoted to metric connections with parallel skew-symmetric torsion in Lorentzian signature. This is motivated by recent progress in the Riemannian signature and by possible applications to supergravity theories. We provide a…

Differential Geometry · Mathematics 2023-01-25 Igor Ernst , Anton S. Galaev

It is observed that on a compact almost complex Calabi-Yau with torsion 6-manifold the Nijenhuis tensor is parallel with respect to the torsion connection. If the torsion is closed then the space is a compact generalized gradient Ricci…

Differential Geometry · Mathematics 2024-08-21 Stefan Ivanov , Nikola Stanchev

In this paper, we propose a generalization of the Riemann curvature tensor on manifolds (of dimension two or higher) endowed with a Regge metric. Specifically, while all components of the metric tensor are assumed to be smooth within…

Numerical Analysis · Mathematics 2026-01-12 Jay Gopalakrishnan , Michael Neunteufel , Joachim Schöberl , Max Wardetzky