Magnetic fields in the accretion disks for various inner boundary
  conditions
  The magnetic fields of accretion disks play an important role in studying
their evolution. We may assume that its generation is connected to the dynamo
mechanism, which is similar with that in the galactic disks. Here, we propose a
model of the magnetic field of the accretion disk that uses the same approaches
that have been used for galaxies. It is necessary to obtain the field, which is
expected to be less than the equipartition value, and without destroying the
disk. To do so, it is necessary to formulate the basic properties of the
ionized medium and to estimate the parameters governing the dynamo. We used the
no-z approximation that has been developed for thin disks. We also take
different boundary conditions that can change the value of the field
significantly. We show that the magnetic field strictly depends on the boundary
conditions. Taking zero conditions and the fixed magnetic field condition on
the inner boundary, which are connected to the physical properties of the
accretion disk, we can avoid solutions that are greater than the equipartition
field.
