Construct exact quantum black holes in semiclassical gravity

Construct exact quantum black hole solutions in semiclassical gravity within a regime where the semiclassical approximation remains valid, thereby accounting nonperturbatively for quantum-matter backreaction on the geometry.

Background

The paper treats quantum black holes as solutions of semiclassical Einstein equations in which the geometry responds to the renormalized expectation value of a quantum matter stress tensor. Although perturbative backreaction can sometimes be computed at leading order, the resulting procedure generally cannot be continued reliably to all orders and does not capture nonperturbative quantum effects.

The authors identify the construction of complete, nonperturbative quantum black hole geometries as an unresolved problem. Such solutions are necessary for probing black hole interiors through asymptotic quasinormal modes, because the near-singularity region cannot be controlled using only a finite number of perturbative corrections. The paper uses braneworld holography as a framework that supplies explicit examples in three dimensions, but the broader problem of uncovering quantum black hole solutions in semiclassical gravity remains open.

References

Still, in an appropriate regime of validity, uncovering quantum black hole solutions in semi-classical gravity remains an open problem.

— Quasinormal modes and quantum black hole interiors  (2609.26724 - Coviello et al., 22 Sep 2026) in Section 1, Introduction, subsection “Quantum black holes”

Via this set-up, it was conjectured that quantum black holes can be exactly constructed by searching for classical bulk black holes that localize on ETW branes.

— Quasinormal modes and quantum black hole interiors  (2609.26724 - Coviello et al., 22 Sep 2026) in Section 1, Introduction, subsection “Exact quantum black holes at the end-of-the-world brane”