Green's-function approach to the edge spectral density

It is shown that the conventional many-body techniques used to calculate the Green's functions can be applied to the wide, compressible edge of a quantum Hall bar. The only ansatz we need is the existence of stable density modes that yields a simple equation of motion of the density operators, We derive the spectral density at a finite temperature and show how the tunneling characteristics of a sharp edge can be deduced as a limiting case. [S0163-1829(97)08739-0].