Recent content by D_Cross

Thank you for the reply. I think I almost have it, so under the infinitesimal transformation x'μ=xμ+aμ, we have δΦ(x)=Φ'(x)-Φ(x). Rearranging the first equation gives xμ=x'μ-aμ. so we can rewrite δΦ=Φ'(x-a)-Φ(x), expanding this out gives δΦ=-aμ∂μΦ(x). Now we also have Φ'(x)=e-iPμaμΦ(x), but I...

Homework Statement consider the space-time transformation of translation xμ → x'μ = xμ + aμ where xμ is a point in space-time and aμis a constant 4-vector. Assuming translations are generated by the operator U=e-iPμaμ acting on fields Φ(x), derive the representation of Pμ on the field Φ(x)...

Ok, so I'm still having a bit of a problem here. If Ψ= ei(kx-ωt) and you act on it with the position operator you get xΨ, so is it not an eigenfunction of that operator. Likewise if you act on it with the momentum operator -iħd/dx you return ħkΨ which through de Broglie is momentum p. So since...

Hello, so I have a couple of related questions. 1) If you have a wavefuction Ψ, and act on it with some operator, does it have to give you the same wavefunction back (ie. does the wavefunction have to be an eigenfunction of the operator)? Could you have a wavefunction like e-iħtSin(x)? Since...

Hi, He was given the third Maxwell equation in differential form and asked how he would find the Electric field. Sorry I can't give you much to go on.

How would you determine the electric field from Maxwell's equations? One of my friends was asked this when he went for a Master's interview. Thanks.

Thank you very much, that makes sense, I was just being an idiot.

I am having a problem with this concept, when looking at the fields from a point source. My problem is that the field gets weaker the further it gets from the source, so at any point away from the source should there not be more entering that point than leaving it, and so have a negative...