- #1
teddd
- 62
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Hi guys, can you help me with this?
I'm supposed to calculate the energy momentum for the classic Maxwell Lagrangian, [itex]\mathcal{L}=-\frac{1}{4}F^{\mu\nu}F_{\mu\nu}[/itex] , where [itex]F_{\mu\nu}=\partial_\mu A_\nu-\partial_\nu A_\mu[/itex]
with the well known formula:
[tex]T^{\sigma\rho}=\frac{\delta\mathcal{L}}{\delta \partial_{\sigma} A_\gamma}\partial^\rho A_\gamma-\mathcal{L}g^{\sigma\rho}[/tex]
The point is that I'm not sure on how should I calculate the [tex]\frac{\delta\mathcal{L}}{\delta\partial_\sigma A_\gamma}\partial^\rho A_\gamma=-\frac{1}{4}\frac{\delta\left[(\partial^\mu A^\nu-\partial^\nu A^\mu)(\partial_\mu A_\nu -\partial_\nu A_\mu)\right]}{\delta\partial_\sigma A_\gamma}\partial^\rho A_\gamma[/tex] term; i cannot figure out on which component should i derive.Can you help me?
I'm supposed to calculate the energy momentum for the classic Maxwell Lagrangian, [itex]\mathcal{L}=-\frac{1}{4}F^{\mu\nu}F_{\mu\nu}[/itex] , where [itex]F_{\mu\nu}=\partial_\mu A_\nu-\partial_\nu A_\mu[/itex]
with the well known formula:
[tex]T^{\sigma\rho}=\frac{\delta\mathcal{L}}{\delta \partial_{\sigma} A_\gamma}\partial^\rho A_\gamma-\mathcal{L}g^{\sigma\rho}[/tex]
The point is that I'm not sure on how should I calculate the [tex]\frac{\delta\mathcal{L}}{\delta\partial_\sigma A_\gamma}\partial^\rho A_\gamma=-\frac{1}{4}\frac{\delta\left[(\partial^\mu A^\nu-\partial^\nu A^\mu)(\partial_\mu A_\nu -\partial_\nu A_\mu)\right]}{\delta\partial_\sigma A_\gamma}\partial^\rho A_\gamma[/tex] term; i cannot figure out on which component should i derive.Can you help me?
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