Schramm's Hausdorff-measure problem for SLE: an exact gauge function for the chordal SLE trace, 0 < kappa < 8
For the chordal trace has Hausdorff dimension (Beffara 2008), and Rezaei (2018) proved its -dimensional Hausdorff measure is zero. For a gauge (continuous, nondecreasing, ) let be the corresponding Hausdorff measure. Schramm, in his 2006 ICM collection of problems (Problem 7.1), asked whether the SLE trace has a sigma-finite Hausdorff measure and suggested as a possible gauge. Is there a deterministic gauge such that almost surely for nontrivial trace segments, and if so, which?
- Result
- Proved(see note)
- Status
- Candidate (review pending)
- AI contribution
- AI-discovered
- Method
- Argument
- Field
- Schramm-Loewner evolution; fractal geometry of random curves
- Posed by
- Oded Schramm, Conformally invariant scaling limits: an overview and a collection of problems (ICM 2006), Problem 7.1
- Year posed
- 2006
- Years open
- 20y
- Solved
- 2026-09-26
- Model
- Unreleased internal OpenAI model
- Vendor
- OpenAI
- Collaborators
- —
- Verification
- Unreviewed
- Publication
- Announced
- Collection
- OpenAI math release (October 2026), version adc7f12
- Significance
- 24 / 100
- Disclosed cost
- —
- Wikipedia
- No dedicated article
What was actually shown
For fixed , , the gauge satisfies almost surely for all , and . Corollary 1.2: Schramm's suggested gauge is not sigma-finite on any such segment, so the exponent he proposed is wrong. The September 25 companion first proved existence of an exact (non-closed-form) gauge. Not addressed: , whether the two gauges are equivalent, and the relation of to natural parametrization or Minkowski content.
What the AI did
The release README says every result in openai/math was produced by an unreleased internal OpenAI model with a fixed procedure, on average about three hours of ChatGPT Pro thinking compute per result. This result is not one of the README's two exceptions (the Hodge conjecture for CM abelian varieties and the Re(s) > 11/12 zero-free region). The manuscript is authored 'OpenAI' and names no human author. The family has two manuscripts: 'An exact Hausdorff gauge for SLE' (September 25, 2026) answered the existence question with an implicitly defined moment-integral gauge; the principal manuscript (September 26, 2026) gives an explicit closed-form gauge with an independent proof and shows Schramm's suggested gauge is not sigma-finite.
Verification
No independent mathematician has checked this yet. Checked here: Theorem 1.1 and Corollary 1.2 of the principal manuscript were read against Schramm's Problem 7.1. The release has a Lean challenge (lean/ComparatorChallenges/SLELowerPositivity.json, declaration OAI.SLEExactGauge.sourceLowerMain_proved, solution module present at the pinned commit), not in the formalization catalogue. Its statement, read here, gives only the lower half: almost surely every gauge agreeing with near 0 gives positive measure to every positive-time segment. Finiteness, the expected bound in disks, and the companion's gauge are not formalized, so the headline is not covered and the tier stays unreviewed; not rebuilt here. Each is fixed; no uniformity in and no identification with natural parametrization is claimed.
Sources
- PaperCompanion: An exact Hausdorff gauge for SLE (Sept 25, 2026)
- Lean proofLean (lower positivity only): OAI/Probability/SLE/LowerPositivity.lean
- CodeOpenAI math release: An explicit exact Hausdorff gauge for SLE
- Problem recordSchramm, Conformally invariant scaling limits: an overview and a collection of problems