====== Greens Function Method ====== Explanations in this section should contain no formulas, but instead colloquial things like you would hear them during a coffee break or at a cocktail party. * A great discussion can be found [[http://theory.uchicago.edu/~sethi/Teaching/P221-F2008/DiracandGreenNotes%2808%29.pdf|here]]. The motto in this section is: //the higher the level of abstraction, the better//. /**/ /**/