Results 181 to 190 of about 2,097,491 (204)

Cartan Frames and the General Relativistic Dirac Equation

Journal of Mathematical Physics, 1966
The Dirac equation for spin-½ particles in curved space-time is formulated using Cartan calculus. Unlike previous formulations, this method is easy to use because it expresses the Dirac equation in terms of well known objects like partial derivatives and special relativistic Dirac matrices.
Brill, Dieter R., Cohen, Jeffrey M.
openaire   +2 more sources

A Geometrically Inspired Model for Kirchhoff Shells with Cartan’s Moving Frames

2020
This work attempts at an entirely novel reformulation of Kirchhoff shells using the theory of moving frames which is a powerful alternative method to describe the geometry of smooth manifolds. In this setup, the defining geometrical features of the non-Euclidean manifold co-evolve with deformation, which means that the model is inherently equipped to ...
Bensingh Dhas, Debasish Roy
openaire   +1 more source

Topological structures of event horizons along framed null Cartan curves in Minkowski space

International Journal of Geometric Methods in Modern Physics, 2022
In this work, we model two event horizons associated with a null Cartan curve as two lightlike hypersurfaces, respectively. We define a lightlike surface and a spacelike surface whose images coincide with the sets of critical values of two event horizons, and meanwhile we present two curves whose images coincide with the sets of critical values of ...
Xintong Yu, Siyao Liu, Zhigang Wang
openaire   +1 more source

Cartan frames and rotating universes

Journal of Physics A: Mathematical and General, 1976
Starting from a given cosmological model, Cartan moving frames are rotated over the manifold of the model to construct rotating cosmological models. A class of solutions with perfect fluid which correspond to rotating models is obtained, from Minkowski space.
openaire   +1 more source

On null Cartan normal isophotic and normal silhouette curves on a timelike surface in Minkowski 3‐space

Mathematical methods in the applied sciences
We introduce generalized Darboux frames along a null Cartan curve lying on a timelike surface in Minkowski space 𝔼13 and define null Cartan normal isophotic and normal silhouette curves in terms of the vector field that lies in the normal plane of the ...
Jelena Djordjević, E. Nešović, Ufuk Ozturk, Esra B. Koç Öztürk   +3 more
semanticscholar   +1 more source

Gravitational interaction in astrophysics in Riemann-Cartan space-time and vacuum torsion

, 2020
The role of space-time torsion in astrophysics in the frame of minimum gauge gravitational theory in Riemann-Cartan space-time is discussed.
A. Minkevich, L. Korenev, V. Klimashonok
semanticscholar   +1 more source

Modeling phononic band gap in microstructured solids using the Riemann–Cartan geometric framework

European Journal of Mechanics. A, Solids
This paper discusses the modeling of acoustic wave fields in microstructured elastic solids within the framework of Riemann-Cartan geometry. We consider a scenario in which microstructural deformations occur significantly faster than those of the bulk ...
Ilya A. Peshkov, L. Le Marrec
semanticscholar   +1 more source

Cartan frame analysis of hearts with infarcts

2017
Ce mémoire se base sur une méthode d'ajustement développée dans [25] pour décrire la géométrie des fibres du coeur de mammifères. En approfondissant le travail auparavant effectué, nous analisons au niveau qualitatif et quantitatif les informations supplémentaires que nous apportent cette analise géométrique réalisée sur des coeurs avec infarctus.
openaire   +1 more source

A Mixed Variational Principle in Nonlinear Elasticity Using Cartan’s Moving Frames and Implementation With Finite Element Exterior Calculus

Computer Methods in Applied Mechanics and Engineering, 2022
Debasish Roy, Junuthula N. Reddy
exaly  

The Cartan Nullspace Protocol — Consciousness as Coordinate Frame for E8 Reality Selection — E8 Intelligence Research

The 8-dimensional Cartan subalgebra of E8 (the 248 − 240 = 8 non-root dimensions) functions as a meta-projector that does not select from the 240 root-realities but *defines the observer's coordinate frame* for selection. The 49 Thoth Laws (7×7) govern the root-lattice Weyl orbits, while the hidden 8th dimension — the Cartan nullspace — encodes the ...
openaire   +1 more source