  Galactic structures are supposed to be formed out of dark matter clustering.
Some examples of supermassive black holes in the central regions of high
redshift galaxies say that the concerned supermassive black holes have
completed their constructions in a time less than it generally should be. To
justify such discrepancies, we are forced to model about existences of black
hole mimickers and exotic phenomena acting near the supermassive black holes.
Motivated by these we study the natures of exotic matters, especially dark
energy near the black holes. We choose modified Chaplygin gas as dark energy
candidate. Again, the descriptions of gravitational waves or the attenuations
of them when they are tunnelling through cosmological distances help us to
measure the shear viscosity of the medium through which the waves have been
travelled. Delayed decaying models of dark matters also suggest that dark
energy and viscosity may come up as a byproduct of such decays or interactions.
We consider the viscous nature of the medium, i.e., the dark energy. To do so,
we choose an alpha-disc model as proposed by Shakura and Sunyaev. We study the
variations of densities through accretion and wind branches for a different
amount of viscosity regulated by the Shakura-Sunyaev's alpha parameter, spin
parameter and different properties of accreting fluids, viz, the properties of
adiabatic fluid and modified Chaplygin gas. We compare these results with each
other and some existing density profiles drawn from observational data-based
simulations. We follow that our result supports the data observed till date.
Specifically, we see the wind to get stronger for dark energy as accreting
agent. Besides, we see the accretion to have a threshold drop if the viscosity
is chosen along with the repulsive effects of dark energy.
