PREPRINT
1F243AE5-D4E3-4716-9021-E064378BBB50

# Effects of finite sizes of atomic nuclei on shear modulus and torsional oscillations in neutron stars

Hajime Sotani, Hajime Togashi, Masatoshi Takano

Submitted on 12 September 2022

## Abstract

The shear modulus of neutron star matter is one of the important properties for determining torsional oscillations in neutron stars. We take into account the effects of finite sizes of spherical nuclei on the shear modulus and examine the frequencies of crustal torsional oscillations. The shear modulus decreases owing to the finite-size effect, which in turn decreases the frequencies of torsional oscillations. In particular, the finite-size effect becomes more crucial for oscillations with a larger azimuthal quantum number and for neutron star models with a weaker density dependence of nuclear symmetry energy. In practice, when one identifies the quasi-periodic oscillations from a neutron star, where the magnetic effect is negligible, with crustal torsional oscillations, the finite-size effect can be more significant at frequencies higher than $\sim 100$ Hz.

## Preprint

Comment: Accepted for publication in MNRAS

Subjects: Nuclear Theory; Astrophysics - High Energy Astrophysical Phenomena