Quantum enforcement of strong cosmic censorship

TL;DR

This paper demonstrates that the trace anomaly in quantum field theory enforces strong cosmic censorship by transforming inner horizons into singularities in various stationary spacetimes, including black holes with different parameters.

Contribution

It shows that the trace anomaly alone is sufficient to enforce strong cosmic censorship across a broad class of stationary spacetimes, extending previous understanding.

Findings

Trace anomaly induces finite stress-energy near the Cauchy horizon.

Inner horizon becomes a null, Tipler-strong singularity due to quantum effects.

Mechanism is local, universal, and applies to various black hole solutions.

Abstract

We show that the trace anomaly of quantum field theory is sufficient to enforce strong cosmic censorship in any stationary spacetime with an inner horizon of nonzero surface gravity. In the two-dimensional dilaton reduction of four-dimensional Einstein-Maxwell theory coupled to $N$ conformal fields, the anomaly-induced Polyakov term yields a finite $\langle T_{vv}\rangle \to \frac{N}{48\pi}\kappa_-^2$ near the Cauchy horizon, while the affine-frame energy grows as $T_{kk}\propto e^{2\kappa_- v}$. The resulting tidal blow-up converts the inner horizon into a null, Tipler-strong singularity. The mechanism is local, universal, and state-independent, and extends to Kerr/Kerr-Newman, $\Lambda>0$, and nonsingular interiors. Thus, the trace anomaly is the minimal quantum ingredient restoring strong cosmic censorship.