On shear-induced turbulence in rotating stars

We review various prescriptions which have been proposed for the turbulent transport of matter and angular mo- mentum in differentially rotating stellar radiation zones. A new prescription is presented for the horizontal transport associated with the anisotropic shear turbulence which is produced by the differential rotation in latitude; this "β-viscosity" is drawn from torque measurements in the classical Couette-Taylor experiment (Richard & Zahn 1999, A&A, 347, 734). Its implementation in a stellar evolution code leads to enhanced mixing, as illustrated by models of a rotating main-sequence star of 1.5 solar mass.