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Salut Sindbad
Non je pense que c'est la même chose, enfin j'en sais pas assez sur la question, mais puisque c'est relatif, ça reviens au même non ?
Voila ce que j'ai trouvé sur un google-group sur la relativité générale, et crois moi ça rigole pas de leur cotés.
Un curieux a posé la question :
The question:
"what is the field of a rapidly moving electric charge
in special relativity?" is treated and answered in any
standard textbook of special relativity. OK. But...I'm in
trouble with the analogous gravitational question:
"what is the field of a rapidly moving (neutral) mass
in general relativity? " My GR textbooks do not answer.
Can someone help me?
Best regards and many thanks
Corrado Massa
[Moderator's note: use Google to search under
"Aichelburg-Sexl" - jb]
Voila ce que lui a répondu un connaisseur :
De : Chris Hillman
Date : Mar 6 nov 2001 03:52
E-mail : Chris Hillman <hill...@math.washington.edu>
Groupes : sci.physics.research
The original paper is:
author = {P. C. Aichelburg and P. U. Sexl},
title = {On the gravitational field of a massless particle},
journal = {Gen. Rel. Grav.},
volume = 2,
year = 1971,
pages ={303}}
and it was motivated by the observation of P. G. Bergmann about the
ultrarelativistic boost of a charged particle in Minkowksi spacetime
(which becomes an EM impulsive plane wave), i.e. the very result mentioned
by Massa.
Several more recent works summarize their method, including the invaluable
monograph:
author = {Valeri P. Frolov and Igor D. Novikov},
title = {Black Hole Physics: Basic Concepts and New Developments},
publisher = {Kluwer},
series = {Fundamental Theories of Physics},
volume = 96,
year = 1998}
The basic idea is to adopt the "spatially isotropic" coordinate chart for
the exterior Schwarzschild vacuum
.
.
.
It should be clear that this is not the
only possible limiting method, and that different methods can give
different results! What the results have in common is that we obtain an
-impulsive- PP wave, i.e. the spacetime is flat except on a single planar
wavefront where the curvature is concentrated, as expressed by the "Dirac
delta function" which appears above. Of course, we can then consider this
to be the limit of a "Gaussian pulse", an ordinary PP wave in the
cartesian harmonic chart
En tout cas, cher Sindbad, si ce Felber a apporté quelque chose de nouveau, on le verra très rapidement dans les revues scientifiques, l'avenir nous le dira
Quant a la solution de Aichelburg-Sexl je crois qu'il y'a quand meme une nuance avec celle attribuee a F.Felber et corrige moi si je me trompe. Le cas d'Aichelburg-Sexl decrit les effets experimentes par un mobile s'approchant ~ C d'une masse (dixit wiki) gravitationnelle spherique en rotation.
Voila ce que j'ai trouvé sur un google-group sur la relativité générale, et crois moi ça rigole pas de leur cotés.
Un curieux a posé la question :
The question:
"what is the field of a rapidly moving electric charge
in special relativity?" is treated and answered in any
standard textbook of special relativity. OK. But...I'm in
trouble with the analogous gravitational question:
"what is the field of a rapidly moving (neutral) mass
in general relativity? " My GR textbooks do not answer.
Can someone help me?
Best regards and many thanks
Corrado Massa
[Moderator's note: use Google to search under
"Aichelburg-Sexl" - jb]
Voila ce que lui a répondu un connaisseur :
De : Chris Hillman
Date : Mar 6 nov 2001 03:52
E-mail : Chris Hillman <hill...@math.washington.edu>
Groupes : sci.physics.research
The original paper is:
author = {P. C. Aichelburg and P. U. Sexl},
title = {On the gravitational field of a massless particle},
journal = {Gen. Rel. Grav.},
volume = 2,
year = 1971,
pages ={303}}
and it was motivated by the observation of P. G. Bergmann about the
ultrarelativistic boost of a charged particle in Minkowksi spacetime
(which becomes an EM impulsive plane wave), i.e. the very result mentioned
by Massa.
Several more recent works summarize their method, including the invaluable
monograph:
author = {Valeri P. Frolov and Igor D. Novikov},
title = {Black Hole Physics: Basic Concepts and New Developments},
publisher = {Kluwer},
series = {Fundamental Theories of Physics},
volume = 96,
year = 1998}
The basic idea is to adopt the "spatially isotropic" coordinate chart for
the exterior Schwarzschild vacuum
.
.
.
It should be clear that this is not the
only possible limiting method, and that different methods can give
different results! What the results have in common is that we obtain an
-impulsive- PP wave, i.e. the spacetime is flat except on a single planar
wavefront where the curvature is concentrated, as expressed by the "Dirac
delta function" which appears above. Of course, we can then consider this
to be the limit of a "Gaussian pulse", an ordinary PP wave in the
cartesian harmonic chart
En tout cas, cher Sindbad, si ce Felber a apporté quelque chose de nouveau, on le verra très rapidement dans les revues scientifiques, l'avenir nous le dira
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