Conveners
(DTP) F2-2 Classical and Quantum Gravity | Gravité classique et quantique (DPT)
- Robie Hennigar
Isolated gravitational systems, such as stationary vacuum black holes, are described in general relativity by spacetimes whose spatial hypersurfacess asymptotically approach flat Euclidean space. The geometric and physical invariants characterizing these solution are very well understood. In five dimensions, one can also consider vacuum solutions whose spatial slices asymptotically approach a...
Drawing upon the canonical quantization of general relativity (GR) in dimensions higher than two, using the Dirac constraint formalism, we propose the loss of covariance as an intrinsic property of the theory. This loss manifests in the first-order Einstein–Hilbert action, where besides first-class constraints, second-class constraints emerge, giving rise to non-standard ghost fields that...
Approach: Although quantum field theories (QFTs) represent a powerful formalism, there is no guarantee that any given QFT proposal will apply to our particular universe. Although a QFT framework has many benefits, by itself, it nevertheless offers a speculative road to quantum gravity. By contrast, here I describe an alternative ontology-driven approach which prioritizes defining an...
We generalize the main result of [1] to Lovelock theory. We find there exists sphere saddle metrics for a partition function at a fixed spatial volume in Lovelock theory. Those stationary points take exactly the same forms as in [1]. The logarithm of $Z$ corresponding to a zero effective cosmological constant indicates the Bakenstein-Hawking entropy of the boundary area and the one...
With insight from examples and physical arguments, the Tolman-Ehrenfest
criterion of thermal equilibrium for test fluids in static spacetimes is
extended to local thermal equilibrium in conformally static geometries.
The temperature of the conformally rescaled fluid scales with the inverse
of the conformal factor, reproducing the evolution of the cosmic microwave
background in...
