A Hamiltonian theory for an elastic earth: Canonical variables and kinetic energy

1990 ◽  
Vol 49 (3) ◽  
pp. 303-326 ◽  
Author(s):  
Juan Getino ◽  
Jose M. Ferr�ndiz
1991 ◽  
Vol 51 (1) ◽  
pp. 17-34 ◽  
Author(s):  
Juan Getino ◽  
José M. Ferrándiz

1988 ◽  
Vol 39 (1) ◽  
pp. 81-102 ◽  
Author(s):  
B. Weyssow ◽  
R. Balescu

The theory of the slow reaction of a charged particle in the combined presence of a strong quasi-static magnetic field and a high-frequency electromagnetic field (generalized oscillation-centre motion) is constructed by using a Hamiltonian formalism with non-canonical variables and pseudo-canonical transformations. The theory combines the features studied in our previous works for the case in which only one of the previously mentioned fields is present. The new averaging transformation is based on the fact that the Larmor frequency of the quasi-static field is of the same order as the external frequency of the high-frequency field. Our theory is manifestly gauge-invariant and involves only physical quantities (particle velocity and electromagnetic fields). Explicit expressions for the drift velocity of the oscillation centre and for the ponderomotive force are derived.


1991 ◽  
Vol 52 (4) ◽  
pp. 381-396 ◽  
Author(s):  
Juan Getino ◽  
Jos� M. Ferr�ndiz

1987 ◽  
Vol 37 (3) ◽  
pp. 467-486 ◽  
Author(s):  
B. Weyssow ◽  
R. Balescu

The theory of the slow reaction of charged particles in the presence of a high-frequency electromagnetic field (oscillation-centre motion) is developed by using a Hamiltonian formalism with non-canonical variables and pseudo-canonical transformations. The flexibility introduced by the latter features allows us to construct a theory which is manifestly gauge-invariant and involves only physical concepts (electromagnetic fields and particle velocities instead of potentials and canonical momenta). A complete description of the oscillation-centre dynamics is derived. The known expressions of the ponderomotive force are derived as special cases of our theory.


In this note a study is made of the field equations which are obtained from varying a Lagrangian subject to auxiliary conditions. It is shown that with proper choice of conjugate variables and the Hamiltonian, they can be brought to canonical forms and thus permit quantization in the usual way. It is then pointed out that for fields with some conjugate variables missing, it is sometimes possible to introduce such auxiliary conditions without affecting the field equations but with the result that all the new canonical variables are present, thus allowing the application of the standard methods of quantization. To illustrate this, the Maxwell field is quantized subject to ∇ . A + c -1 ∂ ɸ /∂ t = 0. The usual supplementary condition on ψ , (∇ . A + c -1 ∂ ɸ /∂ t ) ψ = 0, is found to be shifted to other conditions on ψ . Though in the beginning there are apparently some complications, the final result is simple.


Author(s):  
A. D. Kozlov ◽  
Yu. P. Potekhina

Although joints with synovial cavities and articular surfaces are very variable, they all have one common peculiarity. In most cases, one of the articular surfaces is concave, whereas the other one is convex. During the formation of a joint, the epiphysis, which has less kinetic energy during the movements in the joint, forms a convex surface, whereas large kinetic energy forms the epiphysis with a concave surface. Basing on this concept, the analysis of the structure of the joints, allows to determine forces involved into their formation, and to identify the general patterns of the formation of the skeleton.


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