Inclusion of the effect of radiation pressure on the accretion phenomena in astrophysics.
In the present work, we would like to elaborate on Shakura Sunyaev Alpha disk model. To be more concrete, inclusion of the effect of the radiation pressure on the accretion phenomena have been carefully studied. To summarize, the present modification of Shakura Sunyaev Alpha disk model of disk accretion can be regarded as a new candidate theory of ADAF. Reduction of accreting matter's angular velocity leads to the suppression of the disk luminosity and the surface temperature which essentially implies the transition of the standard accretion disk model from CDAF to ADAF.