RELATIVISTIC ACCRETION DISK STRUCTURE REVISITED

The structure of a thin accretion disk around a Kerr black hole is calculated in order to derive relativistic correction factors with respect to the standard Newtonian disk model. The results are compared with the equations derived in an article by Novikov & Thorne (1973). We find a different factor in the equation of hydrostatic equilibrium; as a consequence the gravitational force from the central black hole is now larger, resulting in a reduced disk height. An additional relativistic factor that has been introduced in the viscous shear for the standard a-disk model turns out to be negligible.