title: Breakdown of wave diffusion in 2D due to loops.
abstract: The validity of the diffusion approximation for the intensity of multiply scattered waves is tested with numerical simulations in a strongly scattering 2D medium of finite extent. We show that the diffusion equation underestimates the intensity and attribute this to both the neglect of recurrent scattering paths and interference within diffusion theory. We present a theory to quantify this discrepancy based on counting all possible scattering paths between point scatterers. Interference phenomena, due to loop paths, are incorporated in a way similar to coherent backscattering.
authors.affiliation: Department of Geophysics and Center for Wave Phenomena, Colorado School of Mines, Golden, CO 80401, USA.
authors.forename: Matthew
authors.initials: M
authors.lastname: Haney
authors.forename: Roel
authors.initials: R
authors.lastname: Snieder