  Considered is spherical shell as a model for visible universe and parameters
that such model must have to comply with the observable data. The topology of
the model requires that motion of all galaxies and light must be confined
inside a spherical shell. Consequently the observable universe cannot be
defined as a sphere centered on the observer, rather it is an arc length within
the volume of the spherical shell. The radius of the shell is 4.46 $\pm$ 0.06
Gpc, which is for factor $\pi$ smaller than radius of a corresponding 3-sphere.
However the event horizon, defined as the arc length inside the shell, has the
size of 14.0 $\pm$ 0.2 Gpc, which is in agreement with the observable data. The
model predicts, without inflation theory, the isotropy and uniformity of the
CMB. It predicts the correct value for the Hubble constant $H_0$ = 67.26 $\pm$
0.90 km/s/Mpc, the cosmic expansion rate $H(z)$, and the speed of the event
horizon in agreement with observations. The theoretical suport for shell model
comes from general relativity, curvature of space by mass, and from holographic
principle. The model explains the reason for the established discrepancy
between the non-covariant version of the holographic principle and the
calculated dimensionless entropy $(S/k)$ for the visible universe, which
exceeds the entropy of a black hole. The model is in accordance with the
distribution of radio sources in space, type Ia data, and data from the Hubble
Ultra Deep Field optical and near-infrared survey.
