  Lorentz gauge theory of gravity was recently introduced. We study the
homogeneous and isotropic universe of this theory. It is shown that some time
after the matter in the universe is diluted enough, at $z \sim 0.6$, the
decelerating expansion shifts spontaneously to an accelerating one without a
dark energy. We discuss that Lorentz gauge theory puts no constraint on the
total energy content of the universe at present time and therefore the
magnitude of vacuum energy predicted by field theory is not contradictory
anymore. It is demonstrated that in this theory the limit on the number of
relativistic particles in the universe is much looser than in GR. An
inflationary mechanism is discussed as well. We show that the theory, unlike
GR, does not require the slow-roll or similar conditions to drive the inflation
at the beginning of the universe.
