Recent content by leastaction

Thanks! Simplify[Im[z], Assumptions -> {Element[z, Reals]}] now works fine... I don't know what I did yesterday...

Hi there! A stupid question maybe but I've found this issue neither in the Mathematica documentation nor in the web: I specified Element[z, Reals] but if I want to evaluate Im[z], Mathematica just says Im[z] again instead of 0. I tried Simplify, FullSimplify and Evaluate but nothing...

Thanks very much! I ask because I've encountered a sum of the above type (with a plus sign) while computing a two-point Green's function and I was wondering if the energy/frequency was conserved...

Hi there! In thermal field theory, the Matsubara frequencies are defined by \nu_n = \frac{2n\pi}{\beta} for bosons and \omega_n = \frac{(2n+1)\pi}{\beta} for fermions. Assuming discrete imaginary time with time indices k=0,\hdots,N, it is easy to obtain the following orthogonality relation...