# Antisolar differential rotation of slowly rotating cool stars

## TL;DR

This paper investigates how slow stellar rotation can lead to antisolar differential rotation, with angular momentum transported towards the poles, through new simulations and analysis of angular momentum transport mechanisms.

## Contribution

It introduces a new explanation for antisolar rotation in slow rotators based on off-diagonal eddy viscosity and simulation results, advancing understanding of stellar rotation profiles.

## Key findings

- Simulations show angular momentum transport towards poles in slow rotation.
- Negative radial gradient of angular velocity causes antisolar rotation.
- Correlation between radial and latitudinal velocities affects temperature profiles.

## Abstract

Rotating stellar convection transports angular momentum towards the equator, generating the characteristic equatorial acceleration of the solar rotation while the radial flux of angular momentum is always inwards. New numerical box simulations for the meridional cross-correlation $\langle u_\theta u_\phi\rangle $, however, reveal the angular momentum transport towards the poles for slow rotation and towards the equator for fast rotation. The explanation is that for slow rotation a negative radial gradient of the angular velocity always appears, which in combination with a so-far neglected rotation-induced off-diagonal eddy viscosity term $\nu_\bot$ provides "antisolar rotation" laws with a decelerated equator. Similarly, the simulations provided positive values for the rotation-induced correlation $\langle u_r u_\theta\rangle $, which is relevant for the resulting latitudinal temperature profiles (cool or warm poles) for slow rotation and negative values for fast rotation. Observations of the differential rotation of slowly rotating stars will therefore lead to a better understanding of the actual stress-strain relation, the heat transport, and the underlying rotating convection.