Higher Order Stability Analysis for Astrophysical Accretion Processes

We have done nth order perturbation analysis of the Navier-Stokes equation with the presence of turbulent viscosity in context of thin accretion flow around a black hole. In order to find the stability criteria, we used Green's function to solve the nth order velocity perturbation equation. Finally, we have proposed a velocity stability criterion which helps to find whether the base flow to be stable for higher order perturbation.