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Reformulation of the Cosmological Constant Problem.
1Department of Physics and Astronomy, The University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada.
Physical Review Letters
|August 16, 2020
Summary
This study reformulates the cosmological constant problem using an inhomogeneous metric, suggesting quantum vacuum fluctuations could be dark energy. The fine-tuning issue is resolved by hiding the vacuum
Area of Science:
- Cosmology
- Quantum Field Theory
- General Relativity
Background:
- The standard cosmological constant problem assumes homogeneous and isotropic spacetime, which is inaccurate at Planck scales.
- Quantum fluctuations at Planck scales lead to highly inhomogeneous and anisotropic spacetime.
- The Friedmann-Lemaître-Robertson-Walker metric is insufficient for describing small-scale spacetime dynamics.
Purpose of the Study:
- To reformulate the cosmological constant problem using a general inhomogeneous metric.
- To investigate the role of quantum vacuum fluctuations in the universe's accelerating expansion.
- To address the fine-tuning problem in cosmology.
Main Methods:
- Utilizing a general inhomogeneous metric to describe spacetime dynamics.
- Analyzing quantum field vacuum stress-energy tensor fluctuations.
- Exploring a weak parametric resonance effect for cosmic acceleration.
Main Results:
- The fine-tuning problem of the cosmological constant does not emerge with the inhomogeneous metric.
- Small-scale spacetime fluctuations effectively mask the large gravitational effect of the quantum vacuum.
- Quantum vacuum fluctuations can potentially act as dark energy.
Conclusions:
- A reformulated cosmological constant problem using inhomogeneous metrics resolves the fine-tuning issue.
- Quantum vacuum fluctuations, driven by spacetime fluctuations, offer a potential explanation for dark energy.
- The proposed mechanism involves a weak parametric resonance driving cosmic acceleration.
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