TY - JOUR
T1 - Skye
T2 - A Differentiable Equation of State
AU - Jermyn, Adam S.
AU - Schwab, Josiah
AU - Bauer, Evan
AU - Timmes, F. X.
AU - Potekhin, Alexander Y.
N1 - Funding Information:
Original content from this work may be used under the terms of the . Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Gordon and Betty Moore Foundation (GBMF) https://doi.org/10.13039/100000936 GBMF7392 National Science Foundation (NSF) https://doi.org/10.13039/100000001 NSF PHY-1748958 National Science Foundation (NSF) https://doi.org/10.13039/100000001 ACI-1663684 National Science Foundation (NSF) https://doi.org/10.13039/100000001 ACI-1663688 National Science Foundation (NSF) https://doi.org/10.13039/100000001 ACI-1663696 National Science Foundation (NSF) https://doi.org/10.13039/100000001 PHY-1430152 Ministry of Science and Higher Education of the Russian Federation (Федеральная целевая программа) https://doi.org/10.13039/501100012190 RAS #075-15-2020-785 yes � 2021. The Author(s). Published by the American Astronomical Society. Creative Commons Attribution 4.0 licence
Publisher Copyright:
© 2021. The Author(s). Published by the American Astronomical Society.
PY - 2021/5/20
Y1 - 2021/5/20
N2 - Stellar evolution and numerical hydrodynamics simulations depend critically on access to fast, accurate, thermodynamically consistent equations of state. We present Skye, a new equation of state for fully ionized matter. Skye includes the effects of positrons, relativity, electron degeneracy, Coulomb interactions, nonlinear mixing effects, and quantum corrections. Skye determines the point of Coulomb crystallization in a self-consistent manner, accounting for mixing and composition effects automatically. A defining feature of this equation of state is that it uses analytic free energy terms and provides thermodynamic quantities using automatic differentiation machinery. Because of this, Skye is easily extended to include new effects by simply writing new terms in the free energy. We also introduce a novel thermodynamic extrapolation scheme for extending analytic fits to the free energy beyond the range of the fitting data while preserving desirable properties like positive entropy and sound speed. We demonstrate Skye in action in the MESA stellar evolution software instrument by computing white dwarf cooling curves.
AB - Stellar evolution and numerical hydrodynamics simulations depend critically on access to fast, accurate, thermodynamically consistent equations of state. We present Skye, a new equation of state for fully ionized matter. Skye includes the effects of positrons, relativity, electron degeneracy, Coulomb interactions, nonlinear mixing effects, and quantum corrections. Skye determines the point of Coulomb crystallization in a self-consistent manner, accounting for mixing and composition effects automatically. A defining feature of this equation of state is that it uses analytic free energy terms and provides thermodynamic quantities using automatic differentiation machinery. Because of this, Skye is easily extended to include new effects by simply writing new terms in the free energy. We also introduce a novel thermodynamic extrapolation scheme for extending analytic fits to the free energy beyond the range of the fitting data while preserving desirable properties like positive entropy and sound speed. We demonstrate Skye in action in the MESA stellar evolution software instrument by computing white dwarf cooling curves.
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U2 - 10.3847/1538-4357/abf48e
DO - 10.3847/1538-4357/abf48e
M3 - Article
AN - SCOPUS:85107304268
SN - 0004-637X
VL - 913
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 1
M1 - 72
ER -