The accuracy, consistency, and speed of an electron-positron equation of state based on table interpolation of the Helmholtz free energy

F. X. Timmes, F. Douglas Swesty

Research output: Contribution to journalArticle

375 Scopus citations

Abstract

An electron-positron equation of state based on table interpolation of the Helmholtz free energy is developed and analyzed. The interpolation scheme guarantees perfect thermodynamic consistency, independent of the interpolating function. The choice of a biquintic Hermite polynomial as the interpolating function results in accurately reproducing the underlying Helmholtz free energy data in the table, and yields derivatives of the pressure, specific entropy, and specific internal energy which are smooth and continuous. The execution speed - evaluated across several different machine architectures, compiler options, and modes of operation - suggests that the Helmholtz equation of state routine is faster than any of the five equation of state routines surveyed by Timmes & Arnett. When an optimal balance of accuracy, thermodynamic consistency, and speed is desirable then the tabular Helmholtz equation of state is an excellent choice, particularly for multidimensional models of stellar phenomena.

Original languageEnglish (US)
Pages (from-to)501-516
Number of pages16
JournalAstrophysical Journal, Supplement Series
Volume126
Issue number2
DOIs
StatePublished - Feb 1 2000
Externally publishedYes

    Fingerprint

Keywords

  • Equation of state
  • Hydrodynamics
  • Methods: numerical
  • Stars: general

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this