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View Full Version : How does the Stress Energy tensor relate to Noether's theorem?


Rearden
Apr8-10, 06:57 PM
Hi,

I was wondering if the stress-energy tensor arose naturally in special relativity in the same way that plain energy and momentum do via Lagrangians. I understand Noether's theorem for particles, but Wikipedia describes the stress-energy tensor as a Noether current; can anyone explain what this is?
Unfortunately, I don't know enough about differential forms to follow the standard definition. The other derivations based on dust etc. all seem a little contrived, deriving vanishing divergence almost as an aftherthought. I'm hoping that this line of inquiry will bring me more satisfaction.

Thanks a lot!

atyy
Apr8-10, 11:09 PM
Try section 1.3.2 of David Tong's http://www.damtp.cam.ac.uk/user/tong/qft.html

Rearden
Apr9-10, 05:39 AM
That's exactly what I need!
Thanks again

Rearden
Apr11-10, 06:41 PM
Sorry to bother again...I now understand the derivation of the Noether current, but which field do I apply it to if I want the standard stress-energy tensor? Is this where "spacetime as a perfect fluid" comes in to play?