Merger-inspired rotation laws and the low-T/W instability in neutron stars

Understand

Implementing a family of differential rotation laws inspired by binary neutron-star merger remnants, we consider the impact of the rotation profile on the low-T/W instability.

• We use time evolutions of the linearised dynamical equations, in Newtonian gravity, to study non-axisymmetric oscillations and identify the unstable modes.
• The presence and evolution of the low-T/W instability is monitored with the canonical energy and angular momentum, while the growth time is extracted from the evolved kinetic energy.
• The results for the new rotation laws highlight similarities with the commonly considered j-constant law.