An incident plane wave e 0 E 0 exp i(k 0 r t) scatters from a target with amplitude f(k) One can prove that f(k 0 ) e 0 k 2 is a causal response function of the sort discussed in Section 18 7 Use this information to prove the wavelength sum rule, lim Re f(x, ko) 0 1 7 St ' (2') ...

To prove the wavelength sum rule well start with the given expression for the causal response function fk0 e0k2 where k0 is the wave vector of the inc ...

An incident plane wave e 0 E 0 exp[i(k 0 r t)] scatters from a

Question:

An incident plane wave ê₀E₀exp[i(k₀· r − ωt)] scatters from a target with amplitude f(k). One can prove that f(k₀) · ê^∗₀/k² is a causal response function of the sort discussed in Section 18.7. Use this information to prove the wavelength sum rule,