Diffusion as a leading dissipative mechanism in superconducting neutron stars

TL;DR

This paper shows that particle diffusion in superconducting neutron star cores is a highly effective dissipative mechanism, surpassing shear and bulk viscosities, significantly impacting neutron star oscillation damping and instability development.

Contribution

It introduces the concept that diffusion is a dominant dissipative process in superconducting neutron stars, affecting their oscillation dynamics and stability analysis.

Findings

Diffusion can be more efficient than shear and bulk viscosities in NSs.

Particle diffusion significantly influences damping times of NS oscillations.

Implications for instabilities and mode coupling during binary NS inspiral.

Abstract

Despite the fact that different particle species can diffuse with respect to each other in neutron star (NS) cores, the effect of particle diffusion on various phenomena associated with NS oscillations is usually ignored. Here we demonstrate that the diffusion can be extremely powerful dissipative mechanism in superconducting NSs. In particular, it can be much more efficient than the shear and bulk viscosities. This result has important implications for the damping times of NS oscillations, development and saturation of dynamical instabilities in NSs, and for the excitation and coupling of oscillation modes during the late inspiral of binary NSs.