1. On the possibility of helicity oscillations in the saturation of the Tayler instability.
- Author
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Bonanno, Alfio and Guarnieri, Filippo
- Subjects
- *
HELICITY of nuclear particles , *LAGRANGIAN points , *MAGNETOHYDRODYNAMICS , *GRAVITATIONAL effects , *ASTRONOMICAL spectroscopy - Abstract
Recent numerical results of current-driven instabilities at low magnetic Prandtl number and high Hartmann number support the possibility of a saturation state characterized by helicity oscillations. We investigate the underlying mechanism by analyzing this possibility using a higher order Landau-Ginzburg effective Lagrangian for the weakly nonlinear amplitude dynamics, where the magnetic and velocity perturbations are linearly dependent. We find that, if the mirror symmetry between left- and right-handed modes is spontaneously broken, it is impossible to achieve an oscillating helical state. We argue that the result is likely to hold also for adding higher order terms and in the presence of an explicit symmetry breaking. We conclude that an oscillating saturating state for the Tayler instability is unlikely to depend on the interaction of chiral modes. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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