Gravity, Geometry and the Quantum
Abstract
After a brief introduction, basic ideas of the quantum Riemannian geometry underlying loop quantum gravity are summarized. To illustrate physical ramifications of quantum geometry, the framework is then applied to homogeneous isotropic cosmology. Quantum geometry effects are shown to replace the big bang by a big bounce. Thus, quantum physics does not stop at the big-bang singularity. Rather there is a pre-big-bang branch joined to the current post-big-bang branch by a `quantum bridge'. Furthermore, thanks to the background independence of loop quantum gravity, evolution is deterministic across the bridge.
Keywords
Cite
@article{arxiv.gr-qc/0605011,
title = {Gravity, Geometry and the Quantum},
author = {Abhay Ashtekar},
journal= {arXiv preprint arXiv:gr-qc/0605011},
year = {2009}
}
Comments
Minor typos corrected, including a factor of $\pi$ in the expression of the critical density. 16 pages, 2 figures. To appear in the Proceedings of the `Einstein Century' Conference, 15-22 July, Paris, edited by J-M Alimi et al (American Institute of Physics)