Hot big bang or slow freeze?
  We confront the big bang for the beginning of the universe with an equivalent
picture of a slow freeze - a very cold and slowly evolving universe. In the
freeze picture the masses of elementary particles increase and the
gravitational constant decreases with cosmic time, while the Newtonian
attraction remains unchanged. The freeze and big bang pictures both describe
the same observations or physical reality. We present a simple "crossover
model" without a big bang singularity. In the infinite past space-time is flat.
Our model is compatible with present observations, describing the generation of
primordial density fluctuations during inflation as well as the present
transition to a dark energy dominated universe.
