Instability - Alfven Wave
The AEI is able to send toward the corona the accretion energy and angular momentumThis mecanism is really efficient, especially in the corotation region. The efficiency is
which is of the order of 1 for raisonnable parameter. This result is valide is the case the no-pertubued magnetic field slowly varies with r.The slow wave do not have a singular behaviour at the corotation as the ALfven waves does. Therefore the previous result may be extend at first approximation to the magnetic field curve on large scale.