Convergence of density-matrix expansions for nuclear interactions

TL;DR

This paper extends density-matrix expansions for nuclear interactions to higher orders, demonstrating improved convergence and proposing a new expansion method that accurately reproduces binding energies for finite-range forces.

Contribution

It introduces higher-order density-matrix expansions and a novel expansion method with superior convergence for nuclear effective forces.

Findings

Enhanced convergence of density-matrix expansions.

Effective quasi-local density functionals for nuclear interactions.

New expansion method accurately reproduces Gogny interaction energies.

Abstract

We extend density-matrix expansions in nuclei to higher orders in derivatives of densities and test their convergence properties. The expansions allow for converting the interaction energies characteristic to finite- and short-range nuclear effective forces into quasi-local density functionals. We also propose a new type of expansion that has excellent convergence properties when benchmarked against the binding energies obtained for the Gogny interaction.