Mechanism of r-mode stability in young rapidly rotating pulsars
  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 $\geq 1.8M_{\odot}$. 
E.E. Kolomeitsev and D.N. Voskresensky
astro-ph.HE astro-ph.SR nucl-th