Results 11 to 20 of about 1,691 (159)

Affine symmetry, geodesics, and homogeneous spacetimes [PDF]

General Relativity and Gravitation, 2018
To appear in General Relativity and Gravitation.
David Maughan, Charles Torre
openaire   +3 more sources

Geodesic vectors of square metrics on 5- dimensional generalized symmetric spaces [PDF]

ریاضی و جامعه
In this paper, we consider the $(\alpha, \beta)$-metric $F=\frac{(\alpha + \beta)^2}{\alpha}$ along with the function $\phi$ with the definition of $\phi(s)=1+2s+s^2$, which is known as a square metric, on 5-dimensional generalized symmetric spaces. Then
Dariush Latifi, Milad Zeinali
doaj   +1 more source

The Sub-Riemannian Limit of Curvatures for Curves and Surfaces and a Gauss-Bonnet Theorem in the Group of Rigid Motions of Minkowski Plane with General Left-Invariant Metric

Journal of Function Spaces, 2021
The group of rigid motions of the Minkowski plane with a general left-invariant metric is denoted by E1,1,gλ1,λ2, where λ1≥λ2>0. It provides a natural 2-parametric deformation family of the Riemannian homogeneous manifold Sol3=E1,1,g1,1 which is the ...
Jianyun Guan, Haiming Liu
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Homogeneous Geodesics in Generalized Wallach Spaces [PDF]

Bulletin of the Belgian Mathematical Society - Simon Stevin, 2017
We classify generalized Wallach spaces which are g.o. spaces. We also investigate homogeneous geodesics in generalized Wallach spaces for any given invariant Riemannian metric and we give some examples.
Arvanitoyeorgos, Andreas, Wang, Yu
openaire   +4 more sources

Two-step Homogeneous Geodesics in Homogeneous Spaces

Taiwanese Journal of Mathematics, 2016
18 ...
Arvanitoyeorgos, Andreas, Panagiotis Souris, Nikolaos   +1 more
openaire   +3 more sources

Geodesic vectors of (α, β)-metrics on hypercomplex 4-dimensional Lie groups [PDF]

Journal of Hyperstructures
In this paper, we consider invariant (α, β)-metrics and describe all geodesic vectors and investigate the set of all homogeneous geodesics on left invariant hypercomplex four dimensional simply connected Lie groups.
Milad Zeinali Laki, Dariush Latifi
doaj   +1 more source

Geodesic deviation equation in generalized hybrid metric-Palatini gravity

European Physical Journal C: Particles and Fields, 2023
In the context of general relativity, the geodesic deviation equation (GDE) relates the Riemann curvature tensor to the relative acceleration of two neighboring geodesics.
S. Golsanamlou, K. Atazadeh, M. Mousavi
doaj   +1 more source

On the initial singularity and extendibility of flat quasi-de Sitter spacetimes

Journal of High Energy Physics, 2023
Inflationary spacetimes have been argued to be past geodesically incomplete in many situations. However, whether the geodesic incompleteness implies the existence of an initial spacetime curvature singularity or whether the spacetime may be extended ...
Ghazal Geshnizjani, Eric Ling, Jerome Quintin   +2 more
doaj   +1 more source

Efficient Superpixel Generation for Polarimetric SAR Images with Cross-Iteration and Hexagonal Initialization

Remote Sensing, 2022
Clustering-based methods of polarimetric synthetic aperture radar (PolSAR) image superpixel generation are popular due to their feasibility and parameter controllability.
Meilin Li, Huanxin Zou, Xianxiang Qin, Zhen Dong, Li Sun, Juan Wei   +5 more
doaj   +1 more source

Geometry of Optimal Control for Control-Affine Systems

Symmetry, Integrability and Geometry: Methods and Applications, 2013
Motivated by the ubiquity of control-affine systems in optimal control theory, we investigate the geometry of point-affine control systems with metric structures in dimensions two and three.
Jeanne N. Clelland, Christopher G. Moseley, George R. Wilkens   +2 more
doaj   +1 more source