Quantum curvature fluctuations and the cosmological constant in a single plaquette quantum gravity model
| Authors | |
|---|---|
| Year of publication | 2025 |
| Type | Article in Periodical |
| Magazine / Source | Classical and Quantum Gravity |
| MU Faculty or unit | |
| Citation | |
| web | https://iopscience.iop.org/article/10.1088/1361-6382/ada90c |
| Doi | http://dx.doi.org/10.1088/1361-6382/ada90c |
| Keywords | quantum gravity; noncommutative riemannian geometry; cosmological constant |
| Description | Understanding the microscopic behavior of spacetime, in particular quantum uncertainty in the Ricci scalar, is critical for developing a theory of quantum gravity and perhaps solving the cosmological constant problem. To test this, we compute this quantity for a simple but exact discrete quantum gravity model based on a single plaquette of spacetime. Our results confirm initial speculations of Wheeler from 1955 in finding a UV divergence in the quantum uncertainty. We further show that this behavior is stable under renormalization, but potentially unstable with the introduction of a cosmological constant, suggesting that a bare cosmological constant is ruled out. |
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