the normalization is not a problem. Dear Suominen, than you for the try,
but this was not the point.
Sympy uses the unitary, ordinary-frequency inverse Fourier transform and
there should be not 1/2pi.
The problem is much deeper; that final result (without the normalization)
is different from
There are two common definitions of inverse Fourier transform depending on
how the frequency variable is interpreted. (See
https://en.wikipedia.org/wiki/Fourier_transform#Other_conventions) The
stackexchange post is using the angular frequency ω that differs by the
factor 2π from frequency
