corner
corner

Phys. Rev. D 70, 124022 (2004) [14 pages]

Coordinate time dependence in quantum gravity

Download: PDF (1,734 kB) Buy this article Export: BibTeX or EndNote (RIS)

Martin Bojowald*
Max-Planck-Institut für Gravitationsphysik, Albert-Einstein-Institut, Am Mühlenberg 1, D-14476 Potsdam, Germany

Parampreet Singh
Institute for Gravitational Physics and Geometry, Pennsylvania State University, University Park, Pennsylvania 16802, USA

Aureliano Skirzewski
Max-Planck-Institut für Gravitationsphysik, Albert-Einstein-Institut, Am Mühlenberg 1, D-14476 Potsdam, Germany

Received 30 August 2004; published 17 December 2004

The intuitive classical space-time picture breaks down in quantum gravity, which makes a comparison and the development of semiclassical techniques quite complicated. Using ingredients of the group averaging method to solve constraints one can nevertheless introduce a classical coordinate time into the quantum theory, and use it to investigate the way a semiclassical continuous description emerges from discrete quantum evolution. Applying this technique to test effective classical equations of loop cosmology and their implications for inflation and bounces, we show that the effective semiclassical theory is in good agreement with the quantum description even at short scales.

© 2004 The American Physical Society

URL:
http://link.aps.org/doi/10.1103/PhysRevD.70.124022
DOI:
10.1103/PhysRevD.70.124022
PACS:
04.60.Pp, 04.25.–g, 98.80.Qc

*Email address: mabo@aei.mpg.de

Email address: singh@gravity.psu.edu

Email address: skirz@aei-potsdam.mpg.de