Angular Momentum Transport in the Central Region of the Galaxy
  We discuss mechanisms for angular momentum transport in the clumpy medium of the circumnuclear disk at the Galactic center. The viscosity due to clump-clump collisions is found to be less than some critical viscosity; this meets the conditions at which a collective mode of nonaxisymmetric shear perturbations in the disk is able to grow until going into the saturation regime where fully developed turbulence is established. We find that the angular momentum transfer due to this turbulent viscosity turns out to comparable to the transport due to magnetic torques. Taken together, the turbulent and magnetic transfer of angular momentum are able to provide the inflow of mass into the central parsec with a rate of about 10^{-2} M_{sun}/yr, consistent with the available data. 
Leonid M. Ozernoy, Alexei M. Fridman, Peter L. Biermann