Existence of sharp random k-SAT density thresholds

For each fixed k≥3, does random k-SAT have a limiting satisfiability threshold αₖ independent of formula size? Clauses are proper, uniformly signed, independent and sampled with replacement.

Why it matters and what counts as progress

Why it matters: A limiting density strengthens a sharp transition whose location could still vary with the number of variables.

What counts as progress: A positive finite αₖ with satisfiability tending to one below it and zero above it; behavior exactly at αₖ is a separate question.

How the problem developed

  1. 1999 · Threshold theorem [1]

    Ehud Friedgut Proved a sharp threshold for random k-SAT, while the threshold location could still depend on the formula size; convergence to a fixed limiting density remained open.

  2. 25 Sept 2026 · Alternative proof [2]

    OpenAI Released a proof that for every fixed k ≥ 3, random k-SAT with independently sampled, uniformly signed clauses on distinct variables has a finite positive limiting threshold.

  3. 5 Oct 2026 · Threshold result [3][2]

    Gaia Carenini Published a proof of the fixed-k satisfiability-threshold conjecture; the OpenAI manuscript credits this concurrent work with priority and presents an alternative proof.

AI contribution

A Limiting Satisfiability Threshold for Every Fixed Clause Size

OpenAI

For every fixed k≥3, random k-SAT with independent uniformly signed proper clauses sampled with replacement has a positive finite limiting density αₖ: satisfiability probability tends to one below αₖ and zero above it. The claim makes no assertion at αₖ.

AI involvementAI-led
ImportanceModest
Technical verificationFormal (Lean 4 with Mathlib)
Human understandingFew
Reported

Sources

  1. Ehud Friedgut, Sharp thresholds for random discrete structures
  2. OpenAI limiting random k-SAT threshold manuscript
  3. Carenini’s priority report
  4. A Limiting Satisfiability Threshold for Every Fixed Clause Size
  5. Lean scope for random SAT
  6. Lean proof of the limiting threshold
  7. OpenAI mathematics release
Website timeline

Publication dates and editorial changes.