Parameters

The 4D TExS equation of state module has a variety of parameters for the calculation of the equation of state. The output file will correspond to the selected parameter choices.

As described in the Quickstart, the user must provide a `config.yaml`_ file. The purpose of this file is to supply all the configuration information required to run the module, such as input data and program options. The rules for this input file are specified in the OpenAPI 3.0.0 Specifications file provided with the module.

Each time the module is executed, it reads the `config.yaml`_ file provided by the user and verifies that the input conforms to the OpenAPI specifications. If it does not, module execution will be unsuccessful. When this happens, make sure to check the logs to identify the issue with your configuration.

It is not necessary to specify every single parameter in the configuration file. If any parameter is omitted, it will be automatically assigned its default value. The default values for each parameter can be found in the OpenAPI specification.

Upon successful execution, the module may produce several output files. These are described in the OpenAPI specification as part of the output schema. Not all of these files are created during every run, and some require the user to specify particular options in the `config.yaml`_ file.

Below are tables providing a brief overview of module’s input, semi-internal and output parameter files.

Input Parameters

The input parameters required to execute the 4D-TExS module are presented in the table below. All parameters have default values in case the user does not specify any. Complete details are given in the module’s OpenAPI specifications.

Category Description	Input Parameter	Default	Description
Grid	`T_min`	`30.0`	Minimum temperature (in `MeV`)
	`T_max`	`500.0`	Maximum temperature (in `MeV`)
	`dT`	`5.0`	Step size in temperature (in `MeV`)
	`mu_B_min`	`-500.0`	Minimum baryon chemical potential (in `MeV`)
	`mu_B_max`	`500.0`	Maximum baryon chemical potential (in `MeV`)
	`dmu_B`	`500`	Step size in baryon chemical potential (in `MeV`)
	`mu_Q_min`	`-500.0`	Minimum electric charge chemical potential (in `MeV`)
	`mu_Q_max`	`500.0`	Maximum electric charge chemical potential (in `MeV`)
	`dmu_Q`	`500`	Step size in electric charge chemical potential (in `MeV`)
	`mu_S_min`	`-500.0`	Minimum strange chemical potential (in `MeV`)
	`mu_S_max`	`500.0`	Maximum strange chemical potential (in `MeV`)
	`dmu_S`	`500`	Step size in strange chemical potential (in `MeV`)

Following is an example of a typical `config.yaml`_ for the 4D-TExS module:

parameters:
  T_min: 30.0
  T_max: 500.
  dT: 7.5
  mu_B_min: -600.0
  mu_B_max: 600.0
  dmu_B: 50.0
  mu_Q_min: -500.0
  mu_Q_max: 500.0
  dmu_Q: 50.0
  mu_S_min: -400.0
  mu_S_max: 400.0
  dmu_S: 50.0
switchers:
  get_P: True
  get_E_dens: True
  get_s_dens: True
  get_B_dens: True
  get_Q_dens: True
  get_S_dens: True

Semi-internal variables

The input parameters required to run the 4D-TExS equation of state are the susceptibilities of lattice QCD equation of state at zero chemical potential. In principle, one can update the values of the susceptibilieties based on a similar spline fit to new lattice data. The data should have a rather small step in temperature, since these table will be spline interpolated, and should be provided with names according to the definition contained in `src/ChiNames.c <https://gitlab.com/nsf-muses/4d-texs/4D-TExS/-/blob/main/src/ChiNames.c?ref_type=heads>`__.

They will only be read after modification of the path (and, if needed, extension of the file name) in the main function of the source code in `src/4D-TExS.c <https://gitlab.com/nsf-muses/4d-texs/4D-TExS/-/blob/main/src/4D-TExS.c?ref_type=heads>`__.

Output Parameters

The output files generated by the module are in .csv format, and are stored in the output/ directory, assuming they have to be produced according to the different switchers.

4D_TExS_eos_output_thermodynamics.csv: this file contains values for thermodynamic observables such as pressure, energy density, charge densities, entropy density, as a function of temperature \(T\) and the conserved charge chemical potentials, i.e. \(\mu_B\), \(\mu_Q\) and \(\mu_S\).