Abstract
We generalize the perturbations theory of loop quantum cosmology to a hydrodynamical form and define an effective curvature perturbation on a uniform-density hypersurfaces . As in the classical cosmology, should be gauge-invariant and conservative on the large scale. The evolutions of both the adiabatic and the nonadiabatic perturbations for a multifluid model are investigated in the framework of the effective hydrodynamical theory of loop quantum cosmology with the inverse-triad correction. We find that, different from the classical cosmology, the evolution of the large-scale nonadiabatic entropy perturbation can be driven by an adiabatic curvature perturbation and this adiabatic source for the nonadiabatic perturbation is a quantum effect. As an application of the related formalism, we study a decay model and give out the numerical results.
- Received 14 November 2011
DOI:https://doi.org/10.1103/PhysRevD.85.023515
© 2012 American Physical Society