G(x,y) is fundamental-solution: L_x G(x,y) = δ(x-y). Solution to L u = f given by u(x) = ∫G(x,y)f(y)dy. Encodes operator-inverse as integral kernel. Backbone of boundary-value-problems + propagator theory.
G(x,y) is fundamental-solution: L_x G(x,y) = δ(x-y). Solution to L u = f given by u(x) = ∫G(x,y)f(y)dy. Encodes operator-inverse as integral kernel. Backbone of boundary-value-problems + propagator theory.