  An attempt is made to explain the spiral structure of spiral galaxies through
a possible rotation of the Universe. To this end, we write down a possible form
of the metric, and we calculate the necessary quantities (Rik, Tik, ...) in
order to form the Einstein equations. We find the two Einstein equations
pertaining to the Robertson-Walker metric and no rotation at all in this way,
if we assume p+e not= 0. There are introduced then two suitable rotational
motions in the universe, and we try to generalize again the Robertson-Walker
metric in this way. The result is again null, since it is found that the
corresponding angular velocities must vanish, for p+e not= 0. A third attempt
is finally done, without restricting ourselves to generalize any existing
cosmological model. We introduce again two suitable rotational motions, and we
form the appropriate Einstein equations. After solving them, we find that the
two rotations, corresponding to the usual rotations on a torus, dictate again
the equation of state p+e = 0. This solution is a steady state one, and it
describes naturally the observationally discovered acceleration of the Universe
(1998), without a cosmological constant and the ambiguous dark energy.
