Quantum cosmological consistency condition for inflation
  We investigate the quantum cosmological tunneling scenario for inflationary
models. Within a path-integral approach, we derive the corresponding tunneling
probability distribution. A sharp peak in this distribution can be interpreted
as the initial condition for inflation and therefore as a quantum cosmological
prediction for its energy scale. This energy scale is also a genuine prediction
of any inflationary model by itself, as the primordial gravitons generated
during inflation leave their imprint in the B-polarization of the cosmic
microwave background. In this way, one can derive a consistency condition for
inflationary models that guarantees compatibility with a tunneling origin and
can lead to a testable quantum cosmological prediction. The general method is
demonstrated explicitly for the model of natural inflation.
