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Stability of de Sitter Spacetime against Infrared Quantum Scalar Field Fluctuations
1APC, AstroParticule et Cosmologie, Université Paris Diderot, CNRS/IN2P3, CEA/Irfu, Observatoire de Paris, Sorbonne Paris Cité, 10, rue Alice Domon et Léonie Duquet, 75205 Paris Cedex 13, France.
Physical Review Letters
|April 24, 2019
Summary
We analyzed quantum scalar field fluctuations in de Sitter geometry using the Wilsonian renormalization group. Nonperturbative effects stabilize spacetime curvature, preventing unbounded corrections in the deep infrared.
Area of Science:
- Cosmology
- Quantum Field Theory
- General Relativity
Background:
- Superhorizon fluctuations of light quantum scalar fields can impact spacetime geometry.
- De Sitter geometry is a key model for cosmic inflation and dark energy.
Purpose of the Study:
- To investigate the backreaction of superhorizon fluctuations on de Sitter geometry.
- To understand the role of nonperturbative effects in stabilizing spacetime curvature.
Main Methods:
- Application of the Wilsonian renormalization group.
- Nonperturbative treatment of gravitationally amplified fluctuations.
- Analytical tracking of renormalization flow of spacetime curvature.
Main Results:
- Identified screening of unbounded loop corrections in the deep infrared.
- Demonstrated stabilization of de Sitter geometry through nonperturbative effects.
- Provided a method to analyze quantum field backreaction in curved spacetimes.
Conclusions:
- Quantum fluctuations, even when amplified, do not necessarily lead to instabilities in de Sitter spacetime.
- Nonperturbative physics plays a crucial role in resolving potential infrared divergences in quantum gravity.
- The Wilsonian renormalization group offers a powerful tool for studying quantum effects in cosmological spacetimes.
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