← openxiv:gr-qc.2026.00001 · gr-qc
A de Sitter region at every black-hole core: discrete causal-set evidence and a canonical regular continuum metric
Explainer at the level of a curious high-schooler. Read the original paper.
Plain language. Few jargon words; every one is defined inline.
Scientists have wondered whether black holes contain a singularity—a point of infinite density and curvature. This paper uses a new theory of gravity to show that the singularity can be replaced by a smooth, finite core. The authors study this using two different approaches. First, they model spacetime as a collection of discrete points (called a causal set) and find that the curvature does not blow up near the center—it stays bounded. Second, they derive a continuous metric (a mathematical description of spacetime) that represents a black hole with a de Sitter core. De Sitter is the same kind of geometry that describes our expanding universe, so the core is like a tiny universe inside the black hole. This metric has no singularity: all curvature measures are finite and reach a maximum at the center. The black hole still has an event horizon, and it agrees with Einstein's gravity in all solar system tests. The paper claims that the classical black hole singularity is resolved at both the discrete and continuous levels. The only inputs are the black hole's mass and a fundamental length scale from the theory.
Explainers are best-effort summaries — they round corners. For the authoritative claims, read the paper itself.