1. The problem statement, all variables and given/known data Derive the Casimir Force on each plate, for a two parallel plate system (L x L), separated at a distance of 'a' apart. The solution was found in en.wikipedia.org/wiki/Casimir_effect#Derivation_of_Casimir_effect_assuming_zeta-regularization. (sorry I couldn't include link yet). Now my question is how did the (2∏)^2 came out in the integral for <E>, I would think it as the constant from fourier transform but I was unable to prove that. Any idea how did that thing pop up of nowhere?