GF transforms

Detailed Description

Transforms between different Green's function representations.

This is a parent group for the transforms that map a Green's function from one representation to another: the Fourier transform (GF Fourier transform), the Legendre/Matsubara transform (GF Legendre-Matsubara transform) and the Padé analytic continuation (GF Padé continuation).

Topics
	GF Fourier transform
	Fourier transform between time and frequency representations.
	GF Legendre-Matsubara transform
	Transform between the Legendre and Matsubara representations.
	GF Padé continuation
	Padé analytic continuation from Matsubara to real frequencies.