Distributed under the MIT License. See LICENSE.txt for details.
These input files are designed to be run on spectre version 2023.01.13, available at https://github.com/sxs-collaboration/spectre/releases/tag/v2023.01.13 and associated with doi https://doi.org/10.5281/zenodo.7535144
The input files follow standard yaml syntax, and can be read using utilities such as pyyaml (https://pyyaml.org/)
For further information about Options as specified in these files, see spectre documentation at https://spectre-code.org/
The equation of state information is encapsulated in the subsection of the file
AnalyticSolution, we intitialize the evolution via solving the TOV equations
with a particular central density, coordinates, and equation of state.
The equations of state we use are PolytropicFluid denoting a simple
polytrope, Spectral, denoting a spectral EoS, or Enthalpy, denoting
the enthalpy parametrization. The enthalpy parametrization must additionally
be provided the low-density equation of state to be used. For example, in the
file labeled enthalpy-pt-mc-70.yaml indicating a PT EoS being evolved
at ~70 meter finite-difference grid spacing, the EoS used is
Enthalpy(Enthalpy(Enthalpy(Spectral))) Indicating there are
3 enthalpy segments supplemented by a low density spectral EoS.
The parameters of the enthalpy parametrization are documented in the spectre
code, in the paper "Simulating neutron stars with a flexible enthalpy-based
equation of state parametrization in SpECTRE" certain variables are used to
denote certain parameters in the input file. See the paper for descriptions.
Note the variable k which sets the scale of trigonometric oscillations is
referred to as TrigScaling in the input file. The variable referred to as
TransitionDeltaEpsilon is unused in any of the input files we provide,
and is not used in the paper. The low-density equation of state
is itself a parameter to the Enthalpy EoS, in the input file an
Enthalpy EoS with a low-density Spectral completion, will
have a field Spectral, which is the low-density spectral EoS
Note that all densities, ReferenceDensity, MinimiumDensity,
ReferenceDensity, and MaximumDensity are given in geometric
units, Msol^{-2}.
For a simple example of an input file with a polytropic parametrization, see polytropic-polytrope-mc-130.yaml
For an example of a pure spectral EoS, see spectral-sly-mc-220.yaml