Quantum nature of the big bang
Some long-standing 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 big-bang 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. © 2006 The American Physical Society.
Publication Source (Journal or Book title)
Physical Review Letters
Ashtekar, A., Pawlowski, T., & Singh, P. (2006). Quantum nature of the big bang. Physical Review Letters, 96 (14) https://doi.org/10.1103/PhysRevLett.96.141301