Non-perturbative calculations of nuclear matter using in-medium similarity renormalization group

TL;DR

This paper develops a non-perturbative ab initio method using IMSRG to calculate properties of infinite nuclear matter with chiral forces, comparing results with other many-body approaches and highlighting discrepancies.

Contribution

It introduces a novel non-perturbative IMSRG approach for nuclear matter calculations with chiral forces, enabling more accurate modeling of dense nuclear systems.

Findings

Different many-body methods show discrepancies with harder nuclear interactions.

IMSRG provides a new framework for studying dense nuclear matter.

Comparison with perturbation and coupled-cluster theories highlights method differences.

Abstract

The non-perturbative {\it ab initio} calculations of infinite nuclear matter using In-Medium Similarity Renormalization Group (IMSRG) method is developed in this work, which enables calculations with chiral two and three-nucleon forces at N$^2$LO and N$^3$LO. Results from the many-body perturbation theory at different orders and coupled-cluster theory are also presented for comparison. It is shown that different many-body approaches lead to obvious discrepancies with a harder nuclear interaction for both pure neutron matter and symmetric nuclear matter. This work provides a novel alternative infrastructure for future studies of dense nuclear matter and strongly-correlated many-body systems.