paper

Robustness of key features of loop quantum cosmology

arXiv:0710.3565 · doi:10.1103/PhysRevD.77.024046

Abstract

Loop quantum cosmology of the k=0 FRW model (with a massless scalar field) is shown to be exactly soluble if the scalar field is used as the internal time already in the classical Hamiltonian theory. Analytical methods are then used i) to show that the quantum bounce is generic; ii) to establish that the matter density has an absolute upper bound which, furthermore, equals the critical density that first emerged in numerical simulations and effective equations; iii) to bring out the precise sense in which the Wheeler DeWitt theory approximates loop quantum cosmology and the sense in which this approximation fails; and iv) to show that discreteness underlying LQC is fundamental. Finally, the model is compared to analogous discussions in the literature and it is pointed out that some of their expectations do not survive a more careful examination. An effort has been made to make the underlying structure transparent also to those who are not familiar with details of loop quantum gravity.

Two changes from the published version: (1) Use of the scalar field clock already in the classical theory leads to a soluble model without any assumptions. sLQC now stands for soluble (rather than simplified) LQC; (2) Some intermediate steps corrected, thanks to a comment by Prof. Ian Lawrie. This also simplified the analysis. Final results unchanged.

References in corpus (16)

Cited by in corpus (329)