Phase conversion dissipation in multicomponent compact stars

TL;DR

This paper introduces a nonlinear damping mechanism for density oscillations in multicomponent compact stars, driven by phase conversions at interfaces, which can significantly limit r-mode amplitudes in hybrid stars.

Contribution

It presents a novel phase conversion dissipation mechanism that effectively saturates r-modes at very low amplitudes in hybrid stars with sharp interfaces.

Findings

Damping mechanism grows nonlinearly with oscillation amplitude.

Mechanism can saturate r-modes at amplitudes around 10^{-10}.

Likely dominant in hybrid stars with sharp interfaces.

Abstract

We propose a mechanism for the damping of density oscillations in multicomponent compact stars. The mechanism is the periodic conversion between different phases, i.e., the movement of the interface between them, induced by pressure oscillations in the star. The damping grows nonlinearly with the amplitude of the oscillation. We study in detail the case of r-modes in a hybrid star with a sharp interface, and we find that this mechanism is powerful enough to saturate the r-mode at very low saturation amplitude, of order $10^{-10}$, and is therefore likely to be the dominant r-mode saturation mechanism in hybrid stars with a sharp interface.