FLUX-LIMITED NEUTRINO DIFFUSION VERSUS MONTE-CARLO NEUTRINO TRANSPORT

Authors
Citation
Ht. Janka, FLUX-LIMITED NEUTRINO DIFFUSION VERSUS MONTE-CARLO NEUTRINO TRANSPORT, Astronomy and astrophysics, 256(2), 1992, pp. 452-458
Citations number
28
Language
INGLESE
art.tipo
Article
Journal title
ISSN journal
0004-6361
Volume
256
Issue
2
Year of publication
1992
Pages
452 - 458
Database
ISI
SICI code
0004-6361(1992)256:2<452:FNDVMN>2.0.ZU;2-4
Abstract
Monte Carlo methods are applied to the transport of neutrinos in super novae and protoneutron stars to check the applicability of currently u sed flux-limited diffusion techniques. Significant and principle diffe rences are found. Motivated by these findings improvements of flux-lim ited diffusion are worked out which allow for a better and more consis tent approximation of neutrino transfer. The introduction of a correct ion function, which carries information about the geometry of the cons idered problem and acts like an opacity term ('artificial opacity'), a llows to achieve consistency between the radiation energy and momentum equations. It controls and governs the evolution of the radiation fie ld towards free streaming when the matter opacity becomes small. Furth ermore, better agreement with solutions of the Boltzmann equation requ ires the use of a new flux-limiter which is deduced from the Monte Car lo results for neutrino transport in a variety of typical situations.