Motion of a particle with extrinsic curvature in an electromagnetic field

2007 ◽  
Vol 85 (3) ◽  
pp. 239-246
Author(s):  
S B Gryb ◽  
D GC McKeon
Keyword(s):  
Electromagnetic Field ◽  
Classical Model ◽  
Equations Of Motion ◽  
Extrinsic Curvature ◽  
Point Particle ◽  
Arc Length ◽  
Rest Energy

The equations of motion for a particle whose free Lagrangian involves not only the arc length of its trajectory, but also its extrinsic curvature, is known to imply that the particle follows a helical path. We examine the parameters associated with this path to see if it can provide a realistic classical model for an electron. The radiation emitted by this point particle while following its helical trajectory is considered, and found to be well below the rest energy of the electron when the helical velocity of the electron is chosen to be 10–4c. PACS No.: 11:15Kc

Classical motion of a point particle with extrinsic curvature

1991 ◽  
Vol 69 (7) ◽  
pp. 830-832 ◽  
Author(s):  
D. G. C. McKeon
Keyword(s):  
Equations Of Motion ◽  
Free Particle ◽  
Coulomb Field ◽  
Extrinsic Curvature ◽  
Point Particle ◽  
Moving Frame ◽  
Arc Length ◽  
Classical Motion ◽  
Time Coordinate ◽  
Special Solutions

We consider the classical motion of a point particle whose Lagrangian involves not only the usual arc length, but also the extrinsic curvature associated with its trajectory. This Lagrangian is independent of the parameterization used to characterize the trajectory; by choosing this parameter to be the time coordinate associated with the position of the particle in space-time, we obtain a Lagrangian dependent on the position, velocity, and acceleration of the particle in a co-moving frame. Some special solutions to the Hamiltonian equations of motion are presented for the case of the free particle and for a particle moving in a Coulomb field.

scholarly journals Interaction of Bianchi type-I anisotropic cloud string cosmological model universe with electromagnetic field

2020 ◽  
Vol 17 (09) ◽  
pp. 2050133
Author(s):  
Kangujam Priyokumar Singh ◽  
Mahbubur Rahman Mollah ◽  
Rajshekhar Roy Baruah ◽  
Meher Daimary
Keyword(s):  
Electromagnetic Field ◽  
Cosmological Model ◽  
Bianchi Type ◽  
Physical Parameters ◽  
Type I ◽  
Field Equations ◽  
Rest Energy ◽  
Model Universe ◽  
Bianchi Type I ◽  
String Cosmological Model

Here, we have investigated the interaction of Bianchi type-I anisotropic cloud string cosmological model universe with electromagnetic field in the context of general relativity. In this paper, the energy-momentum tensor is assumed to be the sum of the rest energy density and string tension density with an electromagnetic field. To obtain exact solution of Einstein’s field equations, we take the average scale factor as an integrating function of time. Also, the dynamics and significance of various physical parameters of model are discussed.

AN ACTION PRINCIPLE FOR MAGNETOHYDRODYNAMICS

1963 ◽  
Vol 41 (12) ◽  
pp. 2241-2251 ◽  
Author(s):  
M. G. Calkin
Keyword(s):  
Electromagnetic Field ◽  
Angular Momentum ◽  
Magnetic Induction ◽  
Vector Potential ◽  
Fluid Velocity ◽  
Equations Of Motion ◽  
Center Of Mass ◽  
Action Principle ◽  
Invariance Properties ◽  
Conservation Of Momentum

The equations of motion of an inviscid, infinitely conducting fluid in an electromagnetic field are transformed into a form suitable for an action principle. An action principle from which these equations may be derived is found. The conservation laws follow from invariance properties of the action. The space–time invariances lead to the conservation of momentum, energy, angular momentum, and center of mass, while the gauge invariances lead to conservation of mass, a generalization of the Helmholtz vortex theorem of hydrodyanmics, and the conservation of the volume integrals of A∙B and v∙B, where A is the vector potential, B is the magnetic induction, and v is the fluid velocity.

Kinematic Aspects in Modeling Large-Amplitude Vibration of Axially Moving Beams

2019 ◽  
Vol 11 (02) ◽  
pp. 1950021 ◽  
Author(s):  
Yuanbin Wang ◽  
Hu Ding ◽  
Li-Qun Chen
Keyword(s):  
Large Amplitude ◽  
Model Equation ◽  
Classical Model ◽  
Equations Of Motion ◽  
Beam Theory ◽  
Governing Equations ◽  
Amplitude Vibration ◽  
Large Amplitude Vibration ◽  
Axially Moving Beams ◽  
Axially Moving

This paper clarified kinematic aspects of motion of axially moving beams undergoing large-amplitude vibration. The kinematics was formulated in the mixed Eulerian–Lagrangian framework. Based on the kinematic analysis, the governing equations of nonlinear vibration were derived from the extended Hamilton principle and the higher-order shear beam theory. The derivation considered the effects of material parameters on the beam deformation. The proposed governing equations were compared with a few previous governing equations. The comparisons show that proposed equations are with higher precision. Besides, the proposed equations can be viewed as the asymptotic governing equations of Lagrange’s equations of motion for large displacement. Finally, the corresponding boundary conditions and the comparison between the presented model equation and classical model equation were provided.

scholarly journals Gauge-independent Theory of Symmetry. I.

1964 ◽  
Vol 17 (4) ◽  
pp. 431 ◽  
Author(s):  
LJ Tassie ◽  
HA Buchdahl
Keyword(s):  
Electromagnetic Field ◽  
Single Particle ◽  
Equations Of Motion ◽  
Classical Mechanics ◽  
Conserved Quantities ◽  
Continuous Symmetry ◽  
Symmetry Properties ◽  
Symmetry Transformations ◽  
Hamiltonian Forms

The invariance of a system under a given transformation of coordinates is usually taken to mean that its Lagrangian is invariant under that transformation. Consequently, whether or not the system is invariant will depend on the gauge used in describing the system. By defining invariance of a system to mean the invariance of its equations of motion, a gauge-independent theory of symmetry properties is obtained for classical mechanics in both the Lagrangian and Hamiltonian forms. The conserved quantities associated with continuous symmetry transformations are obtained. The system of a single particle moving in a given electromagnetic field is considered in detail for various symmetries of the electromagnetic field, and the appropriate conserved quantities are found.

Dynamics of extended bodies in general relativity. I. Momentum and angular momentum

1970 ◽  
Vol 314 (1519) ◽  
pp. 499-527 ◽  
Keyword(s):  
Equations Of Motion ◽  
Potential Energy Function ◽  
Test Body ◽  
The Body ◽  
External Fields ◽  
De Sitter ◽  
Extended Body ◽  
Rest Energy ◽  
Momentum Vector ◽  
De Sitter Universe

Definitions are proposed for the total momentum vector p α and spin tensor S αβ of an extended body in arbitrary gravitational and electromagnetic fields. These are based on the requirement that a symmetry of the external fields should imply conservation of a corresponding component of momentum and spin. The particular case of a test body in a de Sitter universe is considered in detail, and used to support the definition p β S αβ = 0 for the centre of mass. The total rest energy M is defined as the length of the momentum vector. Using equations of motion to be derived in subsequent papers on the basis of these definitions, the time dependence of M is studied, and shown to be expressible as the sum of two contributions, the change in a potential energy function ϕ and a term representing energy inductively absorbed, as in Bondi’s illustration of Tweedledum and Tweedledee. For a body satisfying certain conditions described as ‘dynamical rigidity’, there exists, for motion in arbitrary external fields, a mass constant m such that M = m + ½ S κ Ω κ + ϕ , where Ω k is the angular velocity of the body and S κ its spin vector.

ON THE GEOMETRIC EFFECT OF DARK MATTER

2011 ◽  
Vol 20 (supp01) ◽  
pp. 102-109
Author(s):  
ABRAÃO J. S. CAPISTRANO ◽  
PEDRO I. ODON ◽  
LUIS A. CABRAL
Keyword(s):  
Equations Of Motion ◽  
Radial Distance ◽  
Extrinsic Curvature ◽  
Brane World ◽  
Velocity Curve ◽  
Newtonian Potential ◽  
Potential Approximation ◽  
Small Power ◽  
Geometric Effect ◽  
Visible Matter

We study the effect of the extrinsic curvature on the rotation curves within the context of brane-world, in a 5-d bulk with constant curvature. The covariant equations of motion for the brane-world are applied to determine the modified Newtonian potential approximation and the velocity curve. We consider a static disk galaxy which is composed only of ordinary visible matter. Using the Weyl static metric as a model, we find that the velocity curve is given by the square root of a small power of the radial distance to the galactic core.

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