NONLINEAR SUPERSYMMETRIC SIGMA-MODEL FOR DIFFUSIVE SCATTERING OF CLASSICAL WAVES WITH RESONANCE ENHANCEMENT

We derive a non-linear sigma-model for the transport of light (classic al waves) through a disordered medium. We compare this extension of th e model with the well-established nonlinear sigma-model for the transp ort of electrons (Schrodinger waves) and display similarities of and d ifferences between both cases. Motivated by experimental work (M. van Albada et al., Phys. Rev. Lett., 66 (1991) 3132), we then generalize t he non-linear sigma-model further to include resonance scattering. We find that the form of the effective action is unchanged but that a par ameter of the effective action, the mean level density, is modified in a manner which correctly accounts for the data.