Elastic properties of polycrystalline dense matter

TL;DR

This paper calculates the effective shear modulus of polycrystalline dense matter in neutron stars and white dwarfs, revealing that previous estimates overstate the shear modulus by about 28%, which impacts stellar oscillation models.

Contribution

It introduces a self-consistent method to accurately determine the shear modulus of polycrystalline matter in astrophysical contexts, correcting prior overestimations.

Findings

Previous models overestimate shear modulus by ~28%.

The self-consistent theory provides more accurate elastic property estimates.

Implications for models of stellar oscillations and neutron star crusts.

Abstract

Elastic properties of the solid regions of neutron star crusts and white dwarfs play an important role in theories of stellar oscillations. Matter in compact stars is presumably polycrystalline and, since the elastic properties of single crystals of such matter are very anisotropic, it is necessary to relate elastic properties of the polycrystal to those of a single crystal. We calculate the effective shear modulus of polycrystalline matter with randomly oriented crystallites using a self-consistent theory that has been very successful in applications to terrestrial materials and show that previous calculations overestimate the shear modulus by approximately 28%.