Addition of tabulated equation of state and neutrino leakage support to IllinoisGRMHD

TL;DR

This paper introduces new microphysical EOS and neutrino leakage support to IllinoisGRMHD, validated through tests and simulations of neutron stars and mergers, enhancing the code's realism and robustness.

Contribution

The paper presents the integration of microphysical EOS and neutrino leakage schemes into IllinoisGRMHD, with validation and application to neutron star simulations.

Findings

Validated robustness on Cartesian AMR grids

Successful simulations of neutron stars and mergers

Open-source implementation with pedagogical documentation

Abstract

We have added support for realistic, microphysical, finite-temperature equations of state (EOS) and neutrino physics via a leakage scheme to IllinoisGRMHD, an open-source GRMHD code for dynamical spacetimes in the Einstein Toolkit. These new features are provided by two new, NRPy+-based codes: NRPyEOS, which performs highly efficient EOS table lookups and interpolations, and NRPyLeakage, which implements a new, AMR-capable neutrino leakage scheme in the Einstein Toolkit. We have performed a series of strenuous validation tests that demonstrate the robustness of these new codes, particularly on the Cartesian AMR grids provided by Carpet. Furthermore, we show results from fully dynamical GRMHD simulations of single unmagnetized neutron stars, and magnetized binary neutron star mergers. This new version of IllinoisGRMHD, as well as NRPyEOS and NRPyLeakage, is pedagogically documented in Jupyter notebooks and fully open source. The codes will be proposed for inclusion in an upcoming version of the Einstein Toolkit.