Recent content by JTPF

I still don't get how to do this :frown: So I should take (∇E)i = ε_{ijk}∂_{j}E_{k} and compare the result with the definition of cross product (A×B)i = ε_{ijk}Α_{j}B_{k}? So (∇E) = ∂_{j}E_{k} = A_{j}B_{k}=AXB=kXE?

Homework Statement The field E(r,t) can be written as a Fourier expansion of plane waves E(r,t)=∫E(k,w)e^{i(kr-wt)}d^{3}kdw with similar expansions for other fields. Need to show the derivation of kXE(k,w)=wB(k,w) from Faraday's law ∇XE(r,t)=-∂B(r,t)/∂t and also the derivation of...

What actually is the "Dirac Point"? I'm trying to find out what actually is the "Dirac Point"?! I've Googled it and searched around on the internet, looked through books, but haven't actually been able to find a definitive definition and explanation, just general references to it within the...