Superfluid r-mode instability window

Determine whether the gravitational-radiation-driven CFS instability of $r$-modes is suppressed in accreting neutron stars and establish the corresponding instability window using realistic mutual friction, temperature profiles, superfluid modes, and equations of state.

Background

Mutual friction and resonance damping can stabilize rr-modes in parts of parameter space, but the outcome depends on uncertain microphysics and stellar structure. The review explicitly identifies the suppression question as unresolved.

References

Whether the CFS instability of $r$-modes is suppressed in accreting neutron stars remains unresolved.

— Superfluidity and Vortex Dynamics in Neutron Stars  (2609.01022 - Link et al., 1 Sep 2026) in Section “Open questions and perspectives” under “Precession, Tkachenko modes, and long-term rotational variability”