An Extension of the Athena++ Framework for General Equations of State
Matthew S. B. Coleman

TL;DR
This paper extends the Athena++ framework to support general equations of state, enabling more accurate modeling of astrophysical phenomena involving complex thermodynamic conditions.
Contribution
The authors modify Athena++ to incorporate arbitrary EOS, including changes to Riemann solvers and EOS calls, validated through complex EOS tests.
Findings
Accurate solutions with linear convergence for complex EOS
Successful modeling of hydrogen ionization and electron-positron regimes
Enhanced Athena++ capabilities for realistic astrophysical simulations
Abstract
We present modifications to the Athena++ framework to enable use of general equations of state (EOS). Part of our motivation for doing so is to model transient astrophysics phenomena, as these types of events are often not well approximated by an ideal gas. This necessitated changes to the Riemann solvers implemented in Athena++. We discuss the adjustments made to the HLLC, and HLLD solvers and EOS calls required for arbitrary EOS. We demonstrate the reliability of our code in a number of tests which utilize a relatively simple, but non-trivial EOS based on hydrogen ionization, appropriate for the transition from atomic to ionized hydrogen. Additionally, we perform tests using an electron-positron Helmholtz EOS, appropriate for regimes where nuclear statistical equilibrium is a good approximation. These new complex EOS tests overall show that our modifications to Athena++ accurately…
Peer Reviews
No public reviews on file for this paper yet. If you reviewed it on a platform where reviews are public (OpenReview, ICLR, NeurIPS, ICML), you can paste yours below so the community can read it here.
Videos
No videos yet. Explain this paper in a talk, walkthrough, or lecture? Add one.
