does r-mode instability limit the spin frequency of neutron stars?
Rmodes are oscillations that occur in rotating fluids. In rapidly rotating neutron stars these modes can be unstable. The instability is driven by the gravitational radiation reaction. The most relvant mode for gravitational radiation emisson is the Rossby wave with L=m=2. This mode is unstable when gravitational driving dominates viscous dissipation. Once the amplitude L=m=2 r-mode passes its parameteric instability threshold amplitude, it excites other near-resonant modes in the system and nonlinear effects become important. Roughly speaking, the r-mode instability converts rotational energy to mode energy and gravitational radiation and the star slows down. We study the limiting spin frequency of neutron stars set by the r-mode instability. This project is a continuation of my thesis research and is in collaboration with Ira Wasserman and Saul Teukolsky (Cornell University). This limiting spin frequency depends on internal neutron star physics such as neutrino cooling and viscous he
