  Recent polarimetric mm-observations of the galactic centre by Wielgus et al.
(2022a) showed sinusoidal loops in the Q-U plane with a duration of one hour.
The loops coincide with a quasi-simultaneous X-ray flare. A promising mechanism
to explain the flaring events are magnetic flux eruptions in magnetically
arrested accretion flows (MAD). In our previous work (Porth et al. 2021), we
studied the accretion flow dynamics during flux eruptions. Here, we extend our
previous study by investigating whether polarization loops can be a signature
produced by magnetic flux eruptions. We find that loops in the Q-U plane are
robustly produced in MAD models as they lead to enhanced emissivity of
compressed disk material due to orbiting flux bundles. A timing analysis of the
synthetic polarized lightcurves demonstrate a polarized excess variability at
timescales of ~ 1 hr. The polarization loops are also clearly imprinted on the
cross-correlation of the Stokes parameters which allows to extract a typical
periodicity of 30 min to 1 hr with some evidence for a spin dependence. These
results are intrinsic to the MAD state and should thus hold for a wide range of
astrophysical objects. A subset of GRMHD simulations without saturated magnetic
flux (single temperature SANE models) also produces Q-U loops. However, in
disagreement with the findings of Wielgus et al. (2022a), loops in these
simulations are quasi-continuous with a low polarization excess
