$\textit{Ab initio}$ Exact Calculation of Strongly-Correlated Nucleonic Matter

TL;DR

This paper uses advanced quantum Monte Carlo methods to perform exact calculations of infinite nucleonic matter, revealing strong correlations that challenge previous approximate methods and informing models of dense matter in astrophysics.

Contribution

It introduces the use of full configuration-interaction quantum Monte Carlo for ab initio calculations of infinite nucleonic matter, providing rigorous benchmarks and new insights into nucleonic correlations.

Findings

Symmetric nuclear matter is strongly correlated.

Previous many-body truncation methods may be insufficient.

Results impact understanding of dense matter in compact stars.

Abstract

Dense nucleonic matter is of vital importance for understanding compact stars and inferring the transition into deconfined quark phase. We present $\textit{ab initio}$ exact calculations of infinite nucleonic matter with the state-of-the-art full configuration-interaction quantum Monte Carlo (FCIQMC) method, enabling us to rigorously benchmark many-body methods and assess the degree to which the nucleonic matter is correlated. This method has been numerically validated by exact diagonalization within a small model space. Calculations of nucleonic matter using chiral nuclear forces reveal that symmetric nuclear matter is strikingly strongly correlated, raising questions on previous $\textit{ab initio}$ calculations of nuclear matter with many-body expansion truncations and offering insights into simultaneous descriptions of finite nuclei and infinite nucleonic matter from first principles.