  A new conjecture is proposed that there are two sorts of matter called
s-matter and v-matter which are symmetric and whose gravitational masses are
opposite to each other, although both masses are positive. Therefore, there are
two sorts of symmetry breaking called V-breaking and S-breaking. In the
S-breaking, s-particles get their masses and form s-galaxies etc., while
v-fermions and v-gauge bosons are still massless and form v-SU(5) singlets.
There is no interaction among the v-SU(5) color-single states except
gravitation so that they distribute loosely in space, cannot be observed and
cause space to expand with an acceleration. When temperature increases to the
critical temperature because space contracts, masses of all particles are zero
so that s-particles and v-particles transform from one to another and the
gravitational mass density becomes negative. Consequently, space stop to
contract and inflation must occur. After reheating, space first expands with a
deceleration and then expands with an acceleration up to now. There is no
space-time singularity. There are the critical temperature, the highest
temperature and the least scale in the universe. A formula describing
distance-redshift is obtained. A huge void is not empty, and is equivalent to a
huge concave lens. The densities of hydrogen in the huge voids must be much
less than that predicted by the conventional theory. The gravitation between
two galaxies with distance long enough will be less than that predicted by the
conventional theory. A black hole with its mass and density big enough will
transform into a white hole. Primordial nucleosynthesis and CMB are explained.
It is possible that the universe is composed of infinite cosmic islands. The
problem of energy conservation is discussed.
