  We review the application of the consistent (or decoherent) histories
formulation of quantum theory to canonical loop quantum cosmology. Conventional
quantum theory relies crucially on "measurements" to convert unrealized quantum
potentialities into physical outcomes that can be assigned probabilities. In
the early universe and other physical contexts in which there are no observers
or measuring apparatus (or indeed, in any closed quantum system), what criteria
determine which alternative outcomes may be realized and what their
probabilities are? In the consistent histories formulation it is the vanishing
of interference between the branch wave functions describing alternative
histories -- as determined by the system's decoherence functional -- that
determines which alternatives may be assigned probabilities. We describe the
consistent histories formulation and how it may be applied to canonical loop
quantum cosmology, describing in detail the application to homogeneous and
isotropic cosmological models with scalar matter. We show how the theory may be
used to make definite physical predictions in the absence of "observers". As an
application, we demonstrate how the theory predicts that loop quantum models
"bounce" from large volume to large volume, while conventional
"Wheeler-DeWitt"-quantized universes are invariably singular. We also briefly
indicate the relation to other work.
