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metrictensor

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- Thread starter metrictensor
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metrictensor

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Angular momentum. Immediate by Noether's theorem for classical fields.

Daniel.

Daniel.

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selfAdjoint

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dextercioby said:Angular momentum. Immediate by Noether's theorem for classical fields.

Daniel.

Conservation of angular momentum is generated by spatatial rotation invariance. Space rotation invariance is indeed part of the Lorentz group. But I suspect the original poster was interested in the symmetries related to the Lorentz boost, not by the spatial rotation part of the Lorentz group.

I seem to recall that this question was discussed before, but I don't recall the conclusion that we came to.

- #5

metrictensor

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I was thinking the same thing but there are many 4-vector invariants in SR. Energy-momentum, space-time. The classical conservation laws have one specific quantity conservered not a variety.selfAdjoint said:

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George Jones

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metrictensor said:

Read the stuff here.

Regards,

George

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Berislav

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Thinking by analogy, shouldn't it imply conservation of the stress-energy tensor?

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Nope, stress- energy tensor is linked to space-time translations.

Daniel.

Daniel.

- #9

yogi

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This should be a straightforward question with an obvious answer - but authors seem to skirt the issue

spatial displacement symmetry - conservation of momentum

temporal displacement symmetry - conservation of energy

isotropic symmetry - conservation of angular momentum

When gauge symmetry is applied to Maxwells's em equations, one consequence is conservation of charge - isn't conservation (invariance) of the spacetime interval also consequent to gauge symmetry?

spatial displacement symmetry - conservation of momentum

temporal displacement symmetry - conservation of energy

isotropic symmetry - conservation of angular momentum

When gauge symmetry is applied to Maxwells's em equations, one consequence is conservation of charge - isn't conservation (invariance) of the spacetime interval also consequent to gauge symmetry?

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- #10

arivero

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It is a funny answer... the position of the center of mass? Ok, in absence of external forces, the center of mass is a preserved quantity, so it makes sense, or sort of.

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