arXiv subjects

Tommaso Bambagiotti

Publications and source records attributed to Tommaso Bambagiotti.

3 recordsLinked to original sources

arXiv2026

Coherent quantum geometry: de Sitter spacetime in different foliations

In any theory of quantum gravity, an interesting question to address is to what extent known solutions of the Einstein field equations can be obtained as expectation values of metric operators on suitable quantum states. In this work, we consider coherent states (to ensure minimum uncertainty) for different foliations of the de~Sitter spacetime and study temporal evolution and coordinate invariance. A general framework will first be introduced for metrics that can be diagonalised globally. We will then find that the normalisability of coherent states in this framework requires using reference frames without coordinate singularities.

gr-qc↗

arXiv2026

Quantum dust cores of rotating black holes

Black holes are spacetimes that should describe the end state of the gravitational collapse of huge amounts of quantum matter. A quantum description of dust cores for black hole geometries that accounts for the large number of matter constituents can be obtained by quantising the geodesic motion of dust particles and finding the corresponding many-body ground state. We here generalise previous works in spherical symmetry to rotating geometries and show the effect of angular momentum on the size of the core and effective interior geometry.

gr-qc↗

arXiv2026

Quantum dust cores of black holes and their quasi-normal modes

The quantum description of a gravitationally collapsed ball of dust proposed in Ref.~\cite{Casadio:2023ymt} is characterised by a linear effective Misner-Sharp-Hernandez mass function describing a matter core hidden by the event horizon. After reviewing the original model and some of its refinements, we investigate the quasi-normal mode spectrum of the resulting spacetime and compare it with the Schwarzschild case. Computations are performed within the WKB approximation, based on the Padé approximants up to thirteenth order. Our analysis shows that deviations from the Schwarzschild spectrum are sensitive to the quantum nature of the core surface.

gr-qc↗