Parametric correlations in energy density functionals

TL;DR

This paper investigates parametric correlations across various covariant density functional theories, revealing that many parameters are correlated and can be reduced, which simplifies the models without losing predictive power.

Contribution

It provides a comprehensive statistical analysis of parametric correlations in different classes of covariant density functional theories, highlighting potential for parameter reduction.

Findings

Parametric correlations are present in all major classes of CDFTs.

In the isoscalar channel, only one parameter is truly independent.

Parameter reduction can simplify functional models without compromising accuracy.

Abstract

Parametric correlations are studied in several classes of covariant density functional theories (CDFTs) using a statistical analysis in a large parameter hyperspace. In the present manuscript, we investigate such correlations for two specific types of models, namely, for models with density dependent meson exchange and for point coupling models. Combined with the results obtained previously in Ref. [1] for a non-linear meson exchange model, these results indicate that parametric correlations exist in all major classes of CDFTs when the functionals are fitted to the ground state properties of finite nuclei and to nuclear matter properties. In particular, for the density dependence in the isoscalar channel only one parameter is really independent. Accounting for these facts potentially allows one to reduce the number of free parameters considerably.