  We carry out high-resolution calculations for the stellar convection zone.
The main purpose of this study is to investigate the effect of a small-scale
dynamo on the differential rotation. The solar differential rotation deviates
from the Taylor-Proudman state in which the angular velocity does not change
along the rotational axis. To break the Taylor-Proudman state deep in the
convection zone, it is thought that a latitudinal entropy gradient is required.
In this study, we find that the small-scale dynamo has three roles in the
deviation of the stellar differential rotation from the Taylor-Proudman state.
1. The shear of the angular velocity is suppressed. This leads to a situation
where the latitudinal entropy gradient efficiently breaks the Taylor-Proudman
state. 2. The perturbation of the entropy is increased with suppressing the
turbulent velocity between up- and downflows. 3. The convection velocity is
reduced. This increases the effect of the rotation on the convection. The
second and third factors increase the latitudinal entropy gradient and break
the Taylor-Proudman state. We find that the efficient small-scale dynamo has a
significant impact on the stellar differential rotation.
