8–11 Sept 2026
University of Southampton
Europe/London timezone

When Force-Free MHD Breaks Down: Dissipation and Emission in Extreme Magnetospheres

Not scheduled
20m
Building 56 (University of Southampton)

Building 56

University of Southampton

Highfield, Southampton, SO17 1BJ, UK
CoCoNuT meeting (9-11 Sept)

Speaker

Jens Mahlmann (Dartmouth College)

Description

Relativistic plasmas in highly magnetized neutron star (NS) magnetospheres, including binary NS mergers and magnetars, are well described by force-free electrodynamics (FFE) on large scales, yet their observable emission is strongly influenced by kinetic physics. Global 3D FFE simulations of interacting binary NS magnetospheres reveal extended current sheets, Kelvin–Helmholtz–driven turbulence, and reconnection flares that launch compressive waves, potentially powering radio and X-ray precursors. I will connect large-scale magnetospheric dynamics to first-principles particle-in-cell (PIC) simulations, like our recent study of wave conversion at relativistic magnetized shocks. Alfvénic perturbations can transform into propagating superluminal O-modes when their frequency exceeds the downstream plasma frequency, providing a mechanism for radio transient generation. Finally, I discuss new GPU-accelerated PIC frameworks incorporating radiation reaction and QED effects, enabling direct modeling of turbulence, pair creation, and radio-wave propagation in extreme magnetospheres, bridging global MHD and plasma microphysics.

Author

Jens Mahlmann (Dartmouth College)

Presentation materials

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