2014/09/29 by Giovanni Montani, G. Montani, F. Cianfrani +5 · 1 citation
Chemistry · Medicine · Physics and Astronomy · #Advanced MRI Techniques and Applications #Advanced NMR Techniques and Applications #FOS: Physical sciences #High Energy Astrophysical Phenomena (astro-ph.HE) #NMR spectroscopy and applications #Plasma Physics (physics.plasm-ph) #astro-ph.HE #physics.plasm-ph
paper · pdf · doi:10.48550/arxiv.1409.8200
10 pages. Major modifications
openalex publication_date 2014/09/29 · arxiv created 2016/07/25 · arxiv updated 2016/07/26 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We analyze the linear stability of an axially symmetric ideal plasma disk, embedded in a magnetic field and endowed with a differential rotation. This study is performed by adopting the magnetic flux function as the fundamental dynamical variable, in order to outline the role played by the co-rotation theorem on the linear mode structure. Using some specific assumptions (e.g. plasma incompressibility and propagation of the perturbations along the background magnetic field), we select the Alfvenic nature of the Magneto-Rotational Instability and, in the geometric optics limit, we determine the dispersion relation describing the linear spectrum. We show how the implementation of the co-rotation theorem (valid for the background configuration) on the linear dynamics produces the cancellation of the vertical derivative of the disk angular velocity (we check such a feature also in the standard vector formalism to facilitate comparison with previous literature, both in the axisymmetric and three-dimensional case). As a result, we clarify that the unstable modes have, for a stratified disk, the same morphology, proper of a thin disk profile, and the z dependence has a simple parametric role.