Horizontal shear instabilities in rotating stellar radiation zones

Stellar interiors are the seat of efficient transport angular momentum all along their evolution. Understanding dependence turbulent triggered by shear instabilities due to differential rotation in stellar radiation zones is mandatory. Indeed, it constitutes one cornerstones rotational and mixing theory which implemented evolution codes predict chemical evolutions stars. We investigate horizontal considering full Coriolis acceleration with both dimensionless component $\tilde{f}$ vertical $f$. performed a linear stability analysis for flow hyperbolic tangent profile, numerically asymptotically using WKBJ approximation. As traditional approximation, we identified inflectional inertial instabilities. The instability destabilized as increases its maximum growth rate significantly, while thermal diffusivity stabilizes similarly case. also strongly affected; instance, inertially unstable regime extended non-diffusive limit $0<f<1+\tilde{f}^{2}/N^{2}$, where $N$ Brunt-V\"ais\"al\"a frequency. More strikingly, high-thermal-diffusivity limit, always at any colatitude $\theta$ except poles (i.e., $0^{\circ}<\theta<180^{\circ}$). Using asymptotic numerical results, propose prescription effective viscosities induced be possibly used models. characteristic time this turbulence short enough redistribute efficiently mix chemicals zones.