Quantum Weyl conjecture
For every spacetime with a singularity if the Coulomb component of the Weyl tensor diverges at —equivalently, if the Newman--Penrose scalar diverges there—then quantum-field probes cannot reach Singularities for which only the radiative Weyl components or diverge need not obstruct quantum-field propagation and may remain accessible.
References
Primary source
Additional references
- Probing of colliding wave spacetimes and a quantum Weyl conjecture — Physical Review D — Ivo Sachs, Marc Schneider
Progress summary
A 2026 paper gives evidence for a new rule about which singularities quantum fields can reach, but the conjecture has not been proved generally.
Ivo Sachs and Marc Schneider propose that quantum fields are blocked by singularities where the Coulomb component of spacetime curvature diverges, while certain other singular structures may remain accessible. The conjecture is motivated by explicit colliding-wave examples, not established in full generality.
2026 supporting examples
The analysis finds that quantum fields cannot reach the strong curvature singularity in the Khan–Penrose spacetime, but may reach and pass through the relevant Cauchy horizon in the Ferrari–Ibáñez spacetime. It formulates the proposed criterion using divergence of the Penrose–Newman scalar ; divergences only in or do not produce the same obstruction. No proof, counterexample, or verification of the conjecture was found.
Current status (as of August 2026): the conjecture has supporting calculations in the analyzed spacetimes but remains open in full generality.
Solutions 0
No solutions have been posted yet.