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mjordan2nd
Nov1-09, 09:35 PM
1. The problem statement, all variables and given/known data

Prove \nabla \bullet E =4 \pi \rho from \partial_{\beta}F^{\alpha \beta}=4 \pi J^{\alpha} where J^{\alpha}=(\rho, J^{1}, J^{2}, J^{3}).

2. Relevant equations

We are given that F_{\alpha \beta} is

0~~~~E_x~~~E_y~~~E_z
-E_x~~~0~~~~-B_z~~B_y
-E_y~~B_z~~~~0~~~-B_x
-E_z~~-B_y~~~B_x~~~0

(Sorry, don't know how to do matrices.)

Raising the indices I should get

0~~~-E_x~~-E_y~~-E_z
E_x~~~0~~~~-B_z~~B_y
E_y~~B_z~~~~0~~~-B_x
E_z~~-B_y~~~B_x~~~0

3. The attempt at a solution

\partial_{\beta}F^{\alpha \beta}=4 \pi J^{\alpha}=>-\partial_{i}F^{0i}=\rho=-\partial_{i}E_{i}. I don't know why I keep getting that pesky negative sign! Can anyone point me in the right direction?

mjordan2nd
Nov1-09, 09:37 PM
For whatever reason I can't edit the latex, but it should say it as follows:

(interestingly enough after this post the op corrected itself)

1. The problem statement, all variables and given/known data

Prove \nabla \bullet E =4 \pi \rho from \partial_{\beta}F^{\alpha \beta}=4 \pi J^{\alpha} where J^{\alpha}=(\rho, J^{1}, J^{2}, J^{3}).

2. Relevant equations

We are given that F_{\alpha \beta} is

0~~~~E_x~~~E_y~~~E_z
-E_x~~~0~~~~-B_z~~B_y
-E_y~~B_z~~~~0~~~-B_x
-E_z~~-B_y~~~B_x~~~0

(Sorry, don't know how to do matrices.)

Raising the indices I should get

0~~~-E_x~~-E_y~~-E_z
E_x~~~0~~~~-B_z~~B_y
E_y~~B_z~~~~0~~~-B_x
E_z~~-B_y~~~B_x~~~0

3. The attempt at a solution

\partial_{\beta}F^{\alpha \beta}=4 \pi J^{\alpha}=>-\partial_{i}F^{0i}=\rho=-\partial_{i}E^{i}. I don't know why I keep getting that pesky negative sign! Can anyone point me in the right direction?

mjordan2nd
Nov1-09, 09:42 PM
Bleh, never mind, I got it. Just got the rows and columns confused somehow... Thanks anyway, sorry for wasting your time.