Speaker
Description
We study the quantum-classical Einstein equation from a Hamiltonian perspective where the classical gravitational phase space variables and matter state evolve self-consistently. Applied to cosmology, we show that the resulting equations with a quantized massive scalar field permit exact semiclassical static universes, where the curvature and cosmological constant $\Lambda$ arise as discrete values associated to the eigenstates of the scalar field. Linear stability analysis reveals stable and unstable modes that are functions of $\Lambda$, and independent of the size and curvature of the static universe. The unstable mode leads to an inflating "emergent" universe. We also show numerically that the classical and quantum-classical evolutions agree at late times.
| Keyword-1 | Quantum Gravity |
|---|---|
| Keyword-2 | Semiclassical Physics |
| Keyword-3 | Inflation |
