  We study the dynamics of homogeneous isotropic three-dimensional worlds
filled with radiation (3R-worlds). It is shown that the dynamics of these
worlds with the additional fourth large-scale spatial dimension leads to an
important effect. At 3R-worlds the forces of repulsion appear. The source of
these forces is the thermal energy of the radiation that fills these worlds. In
the four-dimensional space, these forces are centrifugal. They operate in an
external for 3R-world spatial dimension and stretch it. In the
three-dimensional comoving coordinate system the centrifugal forces shows
themselves as forces of repulsion. Standard Einstein's equations do not
describe these forces.
  Written generalized Einstein's equation describing the dynamics of a
homogeneous isotropic universe, taking into consideration the centrifugal
forces of repulsion. We propose a cosmological model of the universe, based on
these equations. This model apply to explain the observation data.
