A Comparison of Selective Summation Techniques for the Coherent Green's Function in Random Media


  • R. E. Collin


A comparison is given of Keller's method, renormalization techniques, and approximations commonly employed in obtaining approximate solutions to the exact Dyson equation for the coherent field. It is shown that the Dyson equation, Keller's method, and the renormalization theory all lead to identical results. It is also shown that the Dyson equation is the most convenient since it is inherently free of unconnected (factorizable) diagrams.