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This paper explores the generalized projective Riemann curvature in Finsler geometry, focusing on the properties of projectively equivalent Finsler metrics and the invariance of their curvature structures under projective transformations.…

Differential Geometry · Mathematics 2025-11-25 Nasrin Sadeghzadeh , Masoumeh Yaghoubi

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

We study Riemannian manifolds carrying a metric connection with parallel, skew-symmetric and closed torsion, which we call in short PSCT manifolds. We prove that PSCT manifolds always locally split into a product of well-understood factors,…

Differential Geometry · Mathematics 2026-05-14 Andrei Moroianu , Paul Schwahn

This document contains a description of physics entirely based on a geometric presentation: all of the theory is described giving only a pseudo-riemannian manifold (M, g) of dimension n > 5 for which the g tensor is, in studied domains,…

Differential Geometry · Mathematics 2020-09-17 Michel Vaugon

The aim of the present paper is to provide an intrinsic investigation of projective changes in Finlser geometry, following the pullback formalism. Various known local results are generalized and other new intrinsic results are obtained.…

Differential Geometry · Mathematics 2013-04-29 Nabil L. Youssef , S. H. Abed , A. Soleiman

Motivated by the geometrical structures of quantum mechanics, we introduce an almost-complex structure $J$ on the product $M\times M$ of any parallelizable statistical manifold $M$. Then, we use $J$ to extract a pre-symplectic form and a…

Quantum Physics · Physics 2020-05-19 Florio M. Ciaglia , Fabio Di Cosmo , Armando Figueroa , Giuseppe Marmo , Luca Schiavone

In this article, we study quasi-Einstein manifolds with constant scalar curvature. We provide a classification of compact and noncompact (possibly with boundary) $T$-flat quasi-Einstein manifolds with constant scalar curvature, where the…

Differential Geometry · Mathematics 2025-05-27 Johnatan Costa , Ernani Ribeiro , Márcio Santos

A 3-dimensional Riemannian manifold equipped with a tensor structure of type $(1,1)$, whose third power is the identity, is considered. This structure and the metric have circulant matrices with respect to some basis, i.e., these structures…

Differential Geometry · Mathematics 2020-09-22 Iva Dokuzova

A general model for geometric structures on differentiable manifolds is obtained by deforming infinitesimal symmetries. Specifically, this model consists of a Lie algebroid, equipped with an affine connection compatible with the Lie…

Differential Geometry · Mathematics 2012-03-07 Anthony D. Blaom

We investigate the topology and geometry of compact submanifolds in space forms of nonnegative curvature that satisfy a lower bound on the sectional curvature, depending only on the length of the mean curvature vector of the immersion. We…

Differential Geometry · Mathematics 2025-02-17 Theodoros Vlachos

Connections with (skew-symmetric) torsion on non-symmetric Riemannian manifold satisfying the Einstein metricity condition (NGT with torsion) are considered. It is shown that an almost Hermitian manifold is an NGT with torsion if and only…

Differential Geometry · Mathematics 2016-03-23 Stefan Ivanov , Milan Zlatanovic

It is considered a differentiable manifold equipped with a pseudo-Riemannian metric and an almost contact 3-struc\-ture so that an almost contact metric structure and two almost contact B-metric structures are generated. There are…

Differential Geometry · Mathematics 2017-11-21 Mancho Manev

This articles is devoted to a description of the second-order differential geometry of torsion-free almost quaternionic skew-Hermitian manifolds, that is, of quaternionic skew-Hermitian manifolds $(M, Q, \omega)$. We provide a curvature…

Differential Geometry · Mathematics 2024-04-09 Ioannis Chrysikos , Vicente Cortés , Jan Gregorovič

We consider the nonstandard inclusion of SO(3) in SO(5) associated with a 5-dimensional irreducible representation. The tensor $\Upsilon$ representing this reduction is found to be given by a ternary symmetric form with special properties.…

Differential Geometry · Mathematics 2007-05-23 Marcin Bobienski , Pawel Nurowski

A metric projective structure is a manifold equipped with the unparametrised geodesics of some pseudo-Riemannian metric. We make acomprehensive treatment of such structures in the case that there is a projective Weyl curvature nullity…

Differential Geometry · Mathematics 2017-11-28 A. Rod Gover , Vladimir S. Matveev

We study a class of Riemannian manifolds with respect to the covariant derivative of their curvature tensors. We introduce geometrically the class of directed Riemannian manifolds of pointwise constant relative sectional curvature and give…

Differential Geometry · Mathematics 2014-11-14 Georgi Ganchev , Vesselka Mihova

We construct almost complex algebraic curvature tensors for pseudo Hermitian inner products whose skew-symmetric curvature operator has constant Jordan normal form on the set of non-degenerate complex lines.

Differential Geometry · Mathematics 2007-05-23 Peter Gilkey , Raina Ivanova

To explore the properties of space and initial singularities in the context of general relativity, where spacetime becomes poorly defined and no longer belongs to a regular manifold, we examine the evolution of the expansion of timelike…

General Relativity and Quantum Cosmology · Physics 2025-04-04 Abdel Nasser Tawfik , Azzah A. Alshehri , Antonio Pasqua

This paper determined the components of the generalized curvature tensor for the class of Kenmotsu type and established the mentioned class is {\eta}-Einstein manifold when the generalized curvature tensor is flat; the converse holds true…

Differential Geometry · Mathematics 2023-06-22 Mohammed Y. Abass , Habeeb M. Abood

It is shown that conventional "covariant" derivative of the Levi-Civita tensor is not really covariant. Adding compensative terms, it is possible to make it covariant and to be equal to zero. Then one can be introduced a curvature in the…

General Physics · Physics 2009-06-04 A. L. Koshkarov