In this paper the method of renormalization group (RG) [ Phys. Rev. E 54, 376 (1996) ] is related to the well-known approximations of Rytov and Born used in wave propagation in deterministic and random media. Certain problems in linear and nonlinear media are examined from the viewpoint of RG and compared with the literature on Born and Rytov approximations. It is found that the Rytov approximation forms a special case of the asymptotic expansion generated by the RG, and as such it gives a superior approximation to the exact solution compared with its Born counterpart. Analogous conclusions are reached for nonlinear equations with an intensity-dependent index of refraction where the RG recovers the exact solution.
© 2008 Optical Society of America
Original Manuscript: June 23, 2008
Revised Manuscript: July 30, 2008
Manuscript Accepted: July 31, 2008
Published: September 18, 2008
Eleftherios Kirkinis, "Renormalization group interpretation of the Born and Rytov approximations," J. Opt. Soc. Am. A 25, 2499-2508 (2008)