Slowly rotating neutron stars with small differential rotation: equilibrium models and oscillations in the Cowling approximation

Understand

Newly born neutron stars can present differential rotation, even if later it should be suppressed by viscosity or a sufficiently strong magnetic field.

• And in this early stage of its life, a neutron star is expected to have a strong emission of gravitational waves, which could be influenced by the differential rotation.
• We present here a new formalism for modelling differentially rotating neutron stars: working on the slow rotation approximation and assuming a small degree of differential rotation, we show that it is possible to separate variables in the Einstein field equations.
• The dragging of inertial frames is determined by solving three decoupled ODEs.