Rossby wave instability in weakly ionized protoplanetary discs – II. Radial B-fields
Bibliographic record
Abstract
ABSTRACT In the first paper of this series, Paper I investigated the influence of pure azimuthal and vertical magnetic fields on the linear growth of the Rossby wave instability (RWI). In this second paper, we extend the analysis to examine the effect of radial magnetic fields on RWI modes, incorporating all three non-ideal magnetohydrodynamics (MHD) effects – Ohmic resistivity, Hall drift, and ambipolar diffusion. The presence of a radial magnetic field relies on the disc’s vertical shear and vertical magnetic field. We perform radially global linear analyses and solve the matrix eigenvalue problem using the spectral code Dedalus. It is found that in the ideal MHD limit, radial fields amplify the suppressive effect of vertical fields on RWI growth rates, with reductions starting at relatively weak field strengths ($\beta \sim 10^3{\!-\!}10^4$), applicable to protoplanetary discs. In the non-ideal MHD regime, when any of the three non-ideal effects become sufficiently strong, the growth rates revert to their hydrodynamic values.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.001 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.001 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".