Results 21 to 30 of about 1,691 (159)

Is the Universe Anisotropic Right Now? Comparing the Real Universe with the Kasner’s Space-Time

Particles, 2023
We investigate possible astronomical manifestations of space-time anisotropy. The homogeneous vacuum Kasner solution was chosen as a reference anisotropic cosmological model because there are no effects caused by inhomogeneity in this simple model with a
Serge Parnovsky
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Deformed relativistic kinematics on curved spacetime: a geometric approach

European Physical Journal C: Particles and Fields, 2022
Deformed relativistic kinematics have been considered as a way to capture residual effects of quantum gravity. It has been shown that they can be understood geometrically in terms of a curved momentum space on a flat spacetime. In this article we present
Christian Pfeifer, José Javier Relancio
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The affine approach to homogeneous geodesics in homogeneous Finsler spaces [PDF]

Archivum Mathematicum, 2018
In a recent paper, it was claimed that any homogeneous Finsler space of odd dimension admits a homogeneous geodesic through any point. For the proof, the algebraic method dealing with the reductive decomposition of the Lie algebra of the isometry group was used. However, the proof contains a serious gap.
openaire   +2 more sources

Using connectomics for predictive assessment of brain parcellations

NeuroImage, 2021
The organization of the human brain remains elusive, yet is of great importance to the mechanisms of integrative brain function. At the macroscale, its structural and functional interpretation is conventionally assessed at the level of cortical units ...
Kristoffer J. Albers, Karen S. Ambrosen, Matthew G. Liptrot, Tim B. Dyrby, Mikkel N. Schmidt, Morten Mørup   +5 more
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Geodesic orbit and weakly symmetric spray manifolds

Comptes Rendus. Mathématique
In this paper, we introduce the geodesic orbit and weakly symmetric properties in homogeneous spray geometry. When a homogeneous spray manifold is endowed with a reductive decomposition, we use the spray vector field to describe these properties, and ...
Xu, Xiyun, Xu, Ming
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A new twist on the geometry of gravitational plane waves

Journal of High Energy Physics, 2017
The geometry of twisted null geodesic congruences in gravitational plane wave spacetimes is explored, with special focus on homogeneous plane waves.
Graham M. Shore
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A SAR-GMTI Approach Aided by Online Knowledge With an Airborne Multichannel Quad-Pol Radar System

IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing, 2022
In the complicated geographical environment, there will be a seriously deleterious effect to the performance of synthetic aperture radar (SAR)-ground moving target indication (SAR-GMTI) system, because it is difficult to obtain the homogeneous training ...
Chaolei Han, Zhiwei Yang, Guisheng Liao, Qingjun Zhang, Shun He, Huajian Xu   +5 more
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On Surfaces of Exceptional Lorentzian Lie Groups with a Four-Dimensional Isometry Group

Mathematics
In total, geodesic surfaces and their generalizations, namely totally umbilical and parallel surfaces, are well-known topics in Submanifold Theory and have been intensively studied in three-dimensional ambient spaces, both Riemannian and Lorentzian.
Giovanni Calvaruso, Lorenzo Pellegrino
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Generalizing the coupling between geometry and matter: $$f\left( R,L_m,T\right) $$ f R , L m , T gravity

European Physical Journal C: Particles and Fields, 2021
We generalize and unify the $$f\left( R,T\right) $$ f R , T and $$f\left( R,L_m\right) $$ f R , L m type gravity models by assuming that the gravitational Lagrangian is given by an arbitrary function of the Ricci scalar R, of the trace of the energy ...
Zahra Haghani, Tiberiu Harko
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Minimal Maslov number of R-spaces canonically embedded in Einstein-Kähler C-spaces

Complex Manifolds, 2019
An R-space is a compact homogeneous space obtained as an orbit of the isotropy representation of a Riemannian symmetric space. It is known that each R-space has the canonical embedding into a Kähler C-space as a real form, and thus a compact embedded ...
Ohnita Yoshihiro
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