Recent content by MyName

Thanks, I thought that was the case and really appreciate the confirmation.

Homework Statement Consider four real massive scalar fields, \phi_1,\phi_2,\phi_3, and \phi_4, with masses M_1,M_2,M_3,M_4. Let these fields be coupled by the interaction lagrangian \mathcal{L}_{int}=\frac{-M_3}{2}\phi_1\phi_{3}^{2}-\frac{M_4}{2}\phi_2\phi_{4}^{2}. Find the scattering amplitude...

That is a great idea, thanks! I managed to solve it using this idea.

Unfortuntely the end result is unknown, otherwise that'd be a great suggestion, thanks! Yeah, I managed to get to that simplification, which like you said defnitely doesn't cancel, so I guess I must be able to somehow write the quantity as a divergence. I'm sorry, but I don't really understand...

Homework Statement [/B] Let f and g be scalar functions of position. Show that: \nabla f \cdot \nabla(\nabla ^2 g)-\nabla g \cdot \nabla(\nabla ^2f) Can be written as the divergence of some vector function given in terms of f and g. Homework Equations [/B] All the identities given at...

Thats fair enough, Ireally appreciate your time and effort. That makes sense actually. I guess what I said is only true for waves with one spatial compnent! It definitely makes a bit more sense to me now.

No, now i come to think of it there isn't anything stating that k is the wavenumber or that \omega is the angular frequency. If i remember correctly though, i was taught that the coefficients of the spatial variables are always the components of k, and that the time coefficient is always the...

Homework Statement Show whether or not the following functions satisfies Maxwell's Equations in free space. (That is, show whether or not they represent a valid electromagnetic wave). E(x,y,t)=(0,0,E_0 sin(kx-ky+\omega t)) B(x,y,t)=B_0 (sin(kx-ky+\omega t),sin(kx-ky+\omega t),0) Homework...

OHHHH, thank you! I knew I must have been overlooking something simple. Near the surface of a conductor the electric field has to be perpendicula to said surface (in equilibrium). Then you can note that the electric field inside the conductor is zero, apply Gauss's law in integral form and...

Homework Statement A point charge q is located a distance d away from the centre of a grounded conducting sphere of radius R<d. I need to find the charge density on the sphere and the total induced charge on the sphere. This is very similar to example 2 here...