Results 1 to 10 of about 92,362 (201)

Sub-Lorentzian Geometry of Curves and Surfaces in a Lorentzian Lie Group

Advances in Mathematical Physics, 2022
We consider the sub-Lorentzian geometry of curves and surfaces in the Lie group E1,1. Firstly, as an application of Riemannian approximants scheme, we give the definition of Lorentzian approximants scheme for E1,1 which is a sequence of Lorentzian ...
Haiming Liu, Jianyun Guan
doaj   +1 more source

Intrinsic spin Nernst effect of magnons in a noncollinear antiferromagnet

Physical Review Research, 2020
We investigate the intrinsic magnon spin current in a noncollinear antiferromagnetic insulator. We introduce a definition of the magnon spin current in a noncollinear antiferromagnet and find that it is in general nonconserved, but for certain symmetries
Bo Li, Shane Sandhoefner, Alexey A. Kovalev   +2 more
doaj   +1 more source

Intrinsic Regression Models for Positive-Definite Matrices With Applications to Diffusion Tensor Imaging

Journal of the American Statistical Association, 2009
The aim of this paper is to develop an intrinsic regression model for the analysis of positive-definite matrices as responses in a Riemannian manifold and their association with a set of covariates, such as age and gender, in a Euclidean space. The primary motivation and application of the proposed methodology is in medical imaging.
Zhu, Hongtu, Chen, Yasheng, Ibrahim, Joseph G., Li, Yimei, Hall, Colin, Lin, Weili   +5 more
openaire   +4 more sources

Strings in gravity with torsion [PDF]

, 1999
A theory of gravitation in 4D is presented with strings used in the material action in $U_4$ spacetime. It is shown that the string naturally gives rise to torsion.
A. Papapetrou, A. Vilenkin, B. Carter, E. W. Mielke, F. W. Hehl, F. W. Hehl, F. W. Hehl, J. Scherk, J.-P. De Villiers, M. Kalb, N. Turok, R. T. Hammond, R. T. Hammond, R. T. Hammond, R. T. Hammond, Richard T. Hammond, T. Dereli   +16 more
core   +2 more sources

Static Observers in Curved Spaces and Non-inertial Frames in Minkowski Spacetime [PDF]

, 2010
Static observers in curved spacetimes may interpret their proper acceleration as the opposite of a local gravitational field (in the Newtonian sense).
C. Misner, C.-G. Huang, C.-G. Huang, D. Alba, D. Alba, D. Bini, D. Bini, D.J. McManus, E. Minguzzi, E. Minguzzi, E. Minguzzi, F. Dahia, G. Longhi, J.R. Letaw, K. Marzlin, L.G. Jensen, M. Pauri, M.A. Abramowicz, M.P. do Carmo, P. J. Felix da Silva, P.J.F. Silva da, R. Wald, S. Carroll, S. Gao, S. Sonego, S.S. Seahra, W. Rindler   +26 more
core   +1 more source

Covariant Generalisation of Codazzi-Raychaudhuri and Area Change Equations for Relativistic Branes [PDF]

, 1997
In this paper we derive the generalisations of Gauss-Codazzi, Raychaudhuri and area change equations for classical relativistic branes and multidimensional fluids in arbitrary background manifolds with metricity and torsion.
Barrabes, Barrabes, Barrabes, Boisseau, Capovilla, Capovilla, Carter, Carter, Carter, Carter, Carter, Carter, Chen, Chen, Eisenhart, Elias Zafiris, Ellis, Hartley, Hawking, Hindmarsh, Horowicz, Kibble, Kobayashi, Letelier, Raychaudhuri, Schouten, Stachel, Stachel, Stelle, Vilenkin, Wald   +30 more
core   +2 more sources

Monoids, Embedding Functors and Quantum Groups [PDF]

, 2007
We show that the left regular representation \pi_l of a discrete quantum group (A,\Delta) has the absorbing property and forms a monoid (\pi_l,\tilde{m},\tilde{\eta}) in the representation category Rep(A,\Delta).
Artin M., Bichon J., Deligne P., Gabriel P., Kazhdan D., LARS TUSET, Mac Lane S., MICHAEL MÜGER, Müger M.   +8 more
core   +4 more sources

A Stress Tensor for Anti-de Sitter Gravity [PDF]

, 1999
We propose a procedure for computing the boundary stress tensor associated with a gravitating system in asymptotically anti-de Sitter space. Our definition is free of ambiguities encountered by previous attempts, and correctly reproduces the masses and ...
Balasubramanian, Vijay, Kraus, Per
core   +2 more sources

Lifting geometric objects to the dual of the first jet bundle of a bundle fibred over R [PDF]

, 2013
We study natural lifting operations from a bundle E over R to the dual bundle of its first-jet bundle. The main purpose is to define a complete lift of a type (1,1) tensor field on E and to understand all features of its construction.
Sarlet, Willy, Waeyaert, Goedele
core   +3 more sources

Generalized Logarithmic Tensor Nuclear Norm for Hyperspectral-Multispectral Image Fusion via Tensor Ring Decomposition

IEEE Journal of Selected Topics in Applied Earth Observations and Remote Sensing
The fusion of a low-spatial-resolution hyperspectral image (LR-HSI) and a high-spatial-resolution multispectral image (HR-MSI) is an effective way to generate a high-resolution hyperspectral image (HR-HSI).
Jun Zhang, Mengling He, Chengzhi Deng
doaj   +1 more source