General relativistic hydrodynamics code for dynamical spacetimes with curvilinear coordinates, tabulated equations of state, and neutrino physics

TL;DR

The paper introduces GRoovy, a new general relativistic hydrodynamics code capable of simulating complex astrophysical systems with realistic physics in curvilinear coordinates, demonstrating robustness and potential for long-term, high-fidelity simulations.

Contribution

GRoovy is a novel code that models astrophysical systems in full general relativity using singular curvilinear coordinates, incorporating realistic equations of state and neutrino physics.

Findings

Successfully tested on static and dynamical spacetimes

Capable of modeling systems with realistic equations of state

Designed for long-term simulations of neutron star mergers

Abstract

Many astrophysical systems of interest to numerical relativity-such as rapidly rotating stars, black hole accretion disks, and core-collapse supernovae-exhibit near-symmetries. These systems generally consist of a strongly gravitating central object surrounded by an accretion disk, debris, and ejecta. Simulations can efficiently exploit the near-axisymmetry of these systems by reducing the number of points in the angular direction around the near-symmetry axis, enabling efficient simulations over seconds-long timescales with minimal computational expense. In this paper, we introduce GRoovy, a novel code capable of modeling astrophysical systems containing compact objects by solving the equations of general relativistic hydrodynamics (GRHD) in full general relativity using singular curvilinear (spherical-like and cylindrical-like) and Cartesian coordinates. We demonstrate the code's robustness through a battery of challenging GRHD tests, ranging from flat, static spacetimes to curved, dynamical spacetimes. These tests further showcase the code's capabilities in modeling systems with realistic, finite-temperature equations of state and neutrino cooling via a leakage scheme. GRoovy extensively leverages GRHayL, an open-source, modular, and infrastructure-agnostic general relativistic magnetohydrodynamics library built from the highly robust algorithms of IllinoisGRMHD. Long-term simulations of binary neutron star and black hole-neutron star post-merger remnants will benefit greatly from using a future Charm++-parallelized version of GRoovy to study phenomena such as remnant stability, gamma-ray bursts, and nucleosynthesis.