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SUMMARY:Tidal resonances of non-linear gravito-inertial modes in binary ne
 utron stars - Alexis Reboul-Salze (AEI)
DTSTART:20260126T160000Z
DTEND:20260126T170000Z
UID:TALK242461@talks.cam.ac.uk
CONTACT:Loren E. Held
DESCRIPTION:For some short gamma-ray bursts\, a non-thermal precursor flar
 e can be observed a few seconds before mergers. The luminosity and energy 
 of these precursors can be explained by a surface magnetic dipole of 1e13 
 G and the release of magnetoelastic energy when the crust breaks. A recent
 ly-proposed scenario to explain this magnetic field is that during the las
 t seconds of a binary neutron-star merger\, the tidal force can excite gra
 vity (and inertial) modes to large amplitudes. However\, existing estimate
 s for their impact employ linear schemes which may be inaccurate for large
  amplitudes\, as achieved by tidal resonances. In this talk\, I will prese
 nt the first non-linear simulations of excited gravito-inertial modes by t
 he tidal force in a simplified rotating model. These simulations show that
  the axisymmetric differential rotation induced by nonlinear 2g and 1g mod
 es may theoretically be large enough to amplify a magnetic field to ~ 1e14
  G. We also find that\, even without initial rotation\, the neutron star w
 ould be spin-up\, extending the resonance window\, which might lead to hig
 her mode amplitudes than linear predictions. Overall\, these results suppo
 rt that resonant g-modes are able to amplify the magnetic field of a preme
 rger neutron star\, and it further suggests that g-mode resonances might h
 ave a stronger impact on gravitational-wave signals than previously estima
 ted.
LOCATION:MR14 DAMTP and online
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