Independent validation of scalar-field-theory coefficients

Establish the correctness of the coefficients in the scalar field theories derived for interacting active Brownian particles and chiral active Brownian particles by comparing them with independent reference values, such as data from particle-based simulations.

Background

The paper derives expressions for the coefficients of the scalar field theories in terms of microscopic parameters, the interaction potential, and the pair distribution function. However, these expressions depend on closure assumptions and are algebraically complicated.

The authors identify quantitative comparison with particle simulations as an unresolved issue because no independent reference values are available to verify whether the derived microscopic coefficients are correct. Such validation would assess the quantitative predictive power of the coarse-grained theories.