Quantum Nature of the Big Bang
Abstract
Some longstanding issues concerning the quantum nature of the big bang are resolved in the context of homogeneous isotropic models with a scalar field. Specifically, the known results on the resolution of the bigbang singularity in loop quantum cosmology are significantly extended as follows: (i) the scalar field is shown to serve as an internal clock, thereby providing a detailed realization of the “emergent time” idea; (ii) the physical Hilbert space, Dirac observables, and semiclassical states are constructed rigorously; (iii) the Hamiltonian constraint is solved numerically to show that the big bang is replaced by a big bounce. Thanks to the nonperturbative, background independent methods, unlike in other approaches the quantum evolution is deterministic across the deep Planck regime.
 Publication:

Physical Review Letters
 Pub Date:
 April 2006
 DOI:
 10.1103/PhysRevLett.96.141301
 arXiv:
 arXiv:grqc/0602086
 Bibcode:
 2006PhRvL..96n1301A
 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;
 High Energy Physics  Theory
 EPrint:
 Revtex4, 4 Pages, 2 Figures. Minor changes to match the published version in Physical Review Letters