  In the context of inflation, non-vacuum initial states for cosmological
perturbations that possess a built in scale are studied. It is demonstrated
that this assumption leads to a falsifiable class of models. The question of
whether they lead to conflicts with the available observations is addressed.
For this purpose, the power spectrum of the Bardeen potential operator is
calculated and compared with the CMBR anisotropies measurements and the
redshift surveys of galaxies and clusters of galaxies. Generic predictions of
the model are: a high first acoustic peak, the presence of a bump in the matter
power spectrum and non-Gaussian statistics. The details are controlled by the
number of quanta in the non-vacuum initial state. Comparisons with observations
show that there exists a window for the free parameters such that good
agreement between the data and the theoretical predictions is possible.
However, in the case where the initial state is a state with a fixed number of
quanta, it is shown that this number cannot be greater than a few. On the other
hand, if the initial state is a quantum superposition, then a larger class of
initial states could account for the observations, even though the state cannot
be too different from the vacuum. Planned missions such as the MAP and Planck
satellites and the Sloan Survey, will demonstrate whether the new class of
models proposed here represents a viable alternative to the standard theory.
