Tidal deformability in neutron stars from a microscopic point of view

TL;DR

This paper investigates neutron star tidal deformability using a microscopic equation of state based on high-precision nuclear forces, aligning well with observational constraints and ruling out overly stiff models.

Contribution

It provides a microscopic calculation of neutron star tidal deformability incorporating chiral three-neutron forces, offering predictions consistent with multimessenger observations.

Findings

Predicted tidal Love number and deformability are within observational bounds.

Stiff equations of state with radii >13 km are inconsistent with GW170817.

Microscopic approach aligns with multimessenger constraints.

Abstract

We present results for the tidal deformability in neutron stars, the tidal Love number $k_2$, and the effective deformability of a binary system. The microscopic equation of state for cold $\beta$-stable neutron matter is based upon high-precision two-neutron forces and includes the chiral three-neutron forces required at the chosen order. We review and motivate our choices for the high-density continuation of the microscopic equation of state. We discuss our predictions and observe that they are well within multimessenger constraints. In contrast, stiff equations of state that yield radii larger than about 13 km are ruled out by GW170817 constraints.