Talk:Optical theorem

why doesn't anyone defines what a "forward scattering" is!!! — Preceding unsigned comment added by 134.100.172.24 (talk) 18:04, 5 June 2012 (UTC)[reply]

Error in Last Line

The last step requires that:

  Re (f(0)/i) = -Im(f(0))

However the opposite is true:

Re (f(0)/i) = +Im(f(0))

However, this will either change the statement of the optical theorem, or the physical interpretation after this line will need rethinking to explain another sign change. I am not sure how to do this, but the statement of the optical theorem is probably right (matches textbook equations). —Preceding unsigned comment added by 129.110.5.90 (talk) 19:10, 5 August 2010 (UTC)[reply]

Mathematica gives (Integrate[Exp[I k x^2/2/z], {x, -Infinity, Infinity}])^2=ConditionalExpression[(2 I \[Pi] z)/k, Im[k/z] > 0], hence the integrals are wrong. Fixing it now. 2A02:21B4:1E66:8000:845A:81AE:AEC4:2411 (talk) 16:25, 17 December 2022 (UTC)Dan[reply]