Abstract
General relativity promotes space-time to a physical, dynamical object subject to equations of motion. Quantum gravity, accordingly, must provide a quantum framework for space-time, applicable on the smallest distance scales. Just like generic states in quantum mechanics, quantum space-time structures may be highly counterintuitive. But if low-energy effects can be extracted, they shed considerable light on the implications to be expected for a dynamical quantum space-time. Loop quantum gravity has provided several such effects, but even in the symmetry-reduced setting of loop quantum cosmology no complete picture on effective space-time geometries describing especially the regime near the big bang has been obtained. The overall situation regarding space-time structures and cosmology is reviewed here, with an emphasis on the role of dynamical states, effective equations, and general covariance.
Original language | English (US) |
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Pages | 1-16 |
Number of pages | 16 |
State | Published - Dec 1 2009 |
Event | 19th Workshop on General Relativity and Gravitation in Japan, JGRG 2009 - Tokyo, Japan Duration: Nov 30 2009 → Dec 4 2009 |
Other
Other | 19th Workshop on General Relativity and Gravitation in Japan, JGRG 2009 |
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Country/Territory | Japan |
City | Tokyo |
Period | 11/30/09 → 12/4/09 |
All Science Journal Classification (ASJC) codes
- Atomic and Molecular Physics, and Optics