  The mechanism for triggering the universe inflation could be that at very
early periods the time variable was discrete instead of smooth. Alternatively,
and perhaps equivalently, it could be the consequence that the metrics of the
early universe was a strongly concentrated gravitational coherent state with
very high frequency oscillations, allowing local pair creations by a
generalisation to gravity of the Schwinger mechanism, perhaps by creation of
black holes of masses superior to the Planck scale. The lattice spacing between
two clicks in the discrete time picture corresponds to the inverse frequency of
the gravitational coherent state in the other picture. In both cases, a much
lower time than the Planck time might represent a new fundamental scale, giving
new type of physics. To make possible a concrete estimation of the pair
production probability, we propose that the oscillating coherent state metrics
that defines this very early geometry minimises the Einstein gravity action
coupled to interacting 1-,2- and 3-forms. Part of our intuition relies on a
condensed matter analogy with laser-induced superconductivity. An independent
section suggests that the new physical time scale we introduce for the
Markovian discret time of the pre-inflation epoch can be identified with the
stochastic time one uses for standard quantisation in the post-inflation limit.
In the pre-inflation phase its discreteness is the observable driving force for
the universe evolution, while in the post inflation phase it becomes
unobservable and it can can effectively replaced by the continuous time
coordinate of standard quantum field theory.
