Mechanism of r-mode stability in young rapidly rotating pulsars

TL;DR

This paper proposes a new explanation for r-mode stability in young pulsars, emphasizing medium modifications of nucleon interactions and pionic degrees of freedom, without needing direct Urca processes, and predicts a high mass for PSR J0537-6910.

Contribution

It introduces a model considering medium modifications of nucleon interactions to explain r-mode stability in young pulsars, avoiding reliance on direct Urca processes.

Findings

R-mode stability can be explained by medium modifications of nucleon interactions.

The model predicts PSR J0537-6910 has a mass ≥ 1.8 solar masses.

Direct Urca processes are not necessary for stability.

Abstract

We demonstrate that stability of r-modes in young rapidly rotating pulsars might be explained if one takes into account strong medium modifications of the nucleon-nucleon interaction because of the softening of pionic degrees of freedom in dense nucleon matter. Presence of the efficient direct Urca processes is not required. Within our model the most rapidly rotating observed young pulsar PSR J0537-6910 should have the mass $\geq 1.8M_{\odot}$.