Extension of the quantum theory of cosmological perturbations to the Planck era
Abstract
Cosmological perturbations are generally described by quantum fields on (curved but) classical spacetimes. While this strategy has a large domain of validity, it can not be justified in the quantum gravity era where curvature and matter densities are of Planck scale. Using techniques from loop quantum gravity, the standard theory of cosmological perturbations is extended to overcome this limitation. The new framework sharpens conceptual issues by distinguishing between the true and apparent transPlanckian difficulties and provides sufficient conditions under which the true difficulties can be overcome within a quantum gravity theory. In a companion paper, this framework is applied to the standard inflationary model, with interesting implications to theory as well as observations.
 Publication:

Physical Review D
 Pub Date:
 February 2013
 DOI:
 10.1103/PhysRevD.87.043507
 arXiv:
 arXiv:1211.1354
 Bibcode:
 2013PhRvD..87d3507A
 Keywords:

 98.80.Qc;
 04.60.Kz;
 04.60.Pp;
 Quantum cosmology;
 Lower dimensional models;
 minisuperspace models;
 Loop quantum gravity quantum geometry spin foams;
 General Relativity and Quantum Cosmology;
 Astrophysics  Cosmology and Nongalactic Astrophysics;
 High Energy Physics  Theory;
 Mathematical Physics
 EPrint:
 50 pages, no figures. This is first of the two detailed papers which form the basis of Phys. Rev. Lett. 109, 251301 (2012). A few references and clarifications added. Version to appear in Phys. Rev. D