Stack Exchange network consists of 183 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.
So, you first construct the F matrix by knowledge of the Green's function G(x,x'). Then you solve the equation for $\phi_{\vec{k}}$, from which you find $\phi(\vec{x})$. Are these the eigenfunctions you are looking for?
Thanks for sharing the information. I also learned this when reading Jackiw's Dirac prize lecture. However, he did not in that work propose the principle and there was no topological argument therein.
