Miquel Miravet Tenés: The magnetorotational instability and small-scale dynamics in neutron stars

Thursday 28 May 2026, 13:15 → 14:00 Europe/Stockholm

A5:1003 (AlbaNova Main Building)

Insufficient numerical resolution in current grid-based simulations limits the development of turbulence at small scales in neutron stars and their mergers. These unresolved processes can influence the large-scale dynamics and gravitational-wave emission, and neglecting them may compromise the reliability of simulations for comparison with observations. Achieving the resolution required to capture such effects fully, however, is computationally prohibitive.

Subgrid models provide an alternative by representing the impact of unresolved turbulence on the resolved flow, thereby enabling key physical effects to be captured at reduced computational cost. In this talk, I will introduce the framework of large-eddy simulations and review selected state-of-the-art applications in neutron star modelling. I will then present the MHD-instability-induced-turbulence (MInIT) subgrid model, with a focus on its application to turbulence driven by the magnetorotational instability (MRI). In particular, I will discuss its role in the post-merger evolution of neutron stars and in differentially rotating configurations susceptible to the MRI, and present recent results obtained with this approach.