Magnetorotational instability in neutron star mergers: impact of neutrinos

Understand

The merger of two neutron stars may give birth to a long-lived hypermassive neutron star.

• If it harbours a strong magnetic field of magnetar strength, its spin-down could explain several features of short gamma-ray burst afterglows.
• The magnetorotational instability (MRI) has been proposed as a mechanism to amplify the magnetic field to the required strength.
• Previous studies have, however, neglected neutrinos, which may have an important impact on the MRI by inducing a viscosity and drag.