mathlib3

d90e4e18 - feat(analysis/special_functions/gaussian): Fourier transform of Gaussian (#18338)

feat(analysis/special_functions/gaussian): Fourier transform of Gaussian (#18338) Use contour integrals around a rectangular contour to show that the Gaussian is its own Fourier transform. Co-authored-by: Meow <mmew78272@gmail.com> Co-authored-by: sgouezel <sebastien.gouezel@univ-rennes1.fr>