Elastic properties of nuclear pasta in neutron-star crusts

TL;DR

This study investigates the elastic properties of nuclear pasta in neutron-star crusts using a relativistic mean field model, considering various configurations and symmetry energy slopes to improve understanding of their mechanical behavior.

Contribution

The paper introduces a fully three-dimensional approach without the Wigner-Seitz approximation and refines analytic formulas for nuclear pasta elasticity considering different symmetry energy slopes.

Findings

Elastic constants vary significantly with symmetry energy slope.

Improved analytic formulas for elastic properties are proposed.

Elastic properties can differ by a factor of ten depending on conditions.

Abstract

Based on the relativistic mean field (RMF) model with Thomas-Fermi approximation, we investigate the elastic properties of neutron star matter. The elastic constants are estimated by introducing deformations on the nuclear pasta structures in $\beta$-equilibrium, where various crystalline configurations are considered in a fully three-dimensional geometry without the Wigner-Seitz approximation. Two scenarios with different symmetry energy slope ($L = 41.34$ and 89.39 MeV) are examined, where the the elastic constants can vary by ten times. By fitting to the numerical results, we improve the analytic formulae for the elastic properties of nuclear pasta by introducing damping factors.