The VDF potential is a four-vector of the form

\[A^{\mu} = \sum_{i=1}^N C_i \left(\frac{\rho}{\rho_0}\right)^{b_i - 2} \frac{j^{\mu}}{\rho_0} \,,\]

where \(j^{\mu}\) is baryon 4-current, \(\rho\) is baryon density in the local Eckart rest frame, and \(\rho_0\) is the saturation density. The parameters of the potential, the coefficients \(C_i\) and the powers \(b_i\), are fitted to reproduce a chosen set of properties of dense nuclear matter, and in particular these may include describing two first order phase transitions: the well-known phase transition in ordinary nuclear matter, and a transiton at high baryon densities meant to model a possible QCD phase transition (a "QGP-like" phase transition); see https://arxiv.org/pdf/2011.06635.pdf for details and example parameter sets for the case \(N=4\).
The user can decide how many terms \(N\) should enter the potential by populating the coefficients and powers vectors in the config file with a chosen number of entries. The number of coefficients must match the number of powers.

Sat_rhoB (double, required, default 0.160):
The saturation density of nuclear matter, in fm \(^{-3}\)

Coeffs (array<double, N>, required, no default):
Parameters \(C_i\) of the VDF potential in MeV (note: the code automatically converts these to GeV)

Powers (array<double, N>, required, no default):
Parameters \(b_i\) of the VDF potential