(Loop) quantum gravity and the inflationary scenario

Abstract

Quantum gravity, as a fundamental theory of space-time, is expected to reveal how the universe may have started, perhaps during or before an inflationary epoch. It may then leave a potentially observable (but probably minuscule) trace in cosmic large-scale structures that seem to match well with predictions of inflation models. A systematic quest to derive such tiny effects using one approach, loop quantum gravity, has, however, led to unexpected obstacles. Such models remain incomplete, and it is not clear whether loop quantum gravity can be consistent as a full theory. But some surprising effects appear to be generic and would drastically alter our understanding of space-time at large density. These new high-curvature phenomena are a consequence of a widening gap between quantum gravity and ordinary quantum-field theory on a background.

10 pages, 1 figure, invited contribution to a special issue published by the French Academy of Sciences

References in corpus (4)

• Quantum Nature of the Big Bang: Improved dynamics
• Large scale effective theory for cosmological bounces
• Effective Constraints for Quantum Systems
• Quantum Cosmology: Effective Theory

Cited by in corpus (3)

• Spherically symmetric sector of self dual Ashtekar gravity coupled to matter: Anomaly-free algebra of constraints with holonomy corrections
• Bouncing cosmologies via modified gravity in the ADM formalism: Application to Loop Quantum Cosmology
• Immirzi parameter without Immirzi ambiguity: Conformal loop quantization of scalar-tensor gravity