Multi-Frequency General Relativistic Radiation-Hydrodynamics with $\bf{M}_1$ Closure [IMA]

http://arxiv.org/abs/2007.12195


We report on recent upgrades to our general relativistic radiation-magnetohydrodynamics code, Cosmos++, which expands the two-moment, $\bf{M}_1$, radiation treatment from grey to multi-frequency transport, including Doppler and gravitational frequency shifts. The solver accommodates either photon (Bose-Einstein) or neutrino (Fermi-Dirac) statistical distribution functions with absorption, emission, and elastic scattering processes. An implicit scheme is implemented to simultaneously solve the primitive inversion problem together with the radiation-matter coupling source terms, providing stability over a broad range of opacities and optical depths where the interactions terms can be stiff. We discuss our formulations and numerical methods, and validate our methods against a wide variety of test problems spanning optically thin to thick regimes in flat, weakly curved, and strongly curved spacetimes.

Read this paper on arXiv…

P. Anninos and P. Fragile
Mon, 27 Jul 20
-548/60

Comments: 22 pages, 11 figures, submitted to Astrophysical Journal