The Fokker-Planck operator as an asymptotic limit. (English) Zbl 0796.45013

Pomraning, G. C.

Math. Models Methods Appl. Sci. 2, No. 1, 21-36 (1992).

Author’s summary: It is shown that the Fokker-Planck operator describing a highly peaked scattering process in the linear transport equation is a formal asymptotic limit of the exact integral operator. It is also shown that such peaking is a necessary, but not sufficient, condition for the Fokker-Planck operator to be a legitimate description of such scattering. In particular, the widely used Henyey-Greenstein scattering kernel does not possess a Fokker-Planck limit.

Reviewer: J.Voigt (Dresden)

MSC:

45K05	Integro-partial differential equations
82C70	Transport processes in time-dependent statistical mechanics

Keywords:

Fokker-Planck operator; linear transport equation; peaking; Henyey- Greenstein scattering kernel