Kahn’s flow conjecture on the Boolean cube

The question is whether for every increasing antipodal function h on the Boolean cube and every nonnegative allocation of each nonempty Fourier coefficient’s squared mass among its coordinates, the induced linear function flows upward to h₊². This is Kahn’s flow conjecture.

Why it matters and what counts as progress

Why it matters: It asks for a structural flow principle strengthening the known intersecting-family inequalities for every permitted Fourier allocation.

What counts as progress: Prove upward flow for every permitted allocation of Fourier mass, beyond a single preferred allocation, or construct a violating allocation.

How the problem developed

  1. 2018 · Conjecture [1]

    Ehud Friedgut, Jeff Kahn, Gil Kalai and Nathan Keller Formulated the flow conjecture as a strengthening related to Chvátal’s intersecting-family conjecture and Boolean-cube correlation inequalities.

  2. 16 Sept 2026 · Partial result [2]

    Fan Chang, Hong Liu and Miao Liu Posted a sharp correlation inequality proving Chvátal’s conjecture; this result became an input to the later flow argument.

  3. 20 Sept 2026 · Proof claim [3]

    Peter Keevash Posted a proof of Kahn’s flow conjecture, using the Chang–Liu–Liu inequality and crediting GPT-6 Astra with finding the proof within a human-suggested approach.

AI contribution

Sources

  1. Friedgut–Kahn–Kalai–Keller flow conjecture
  2. Fan Chang, Hong Liu and Miao Liu, A proof of Chvátal’s conjecture via a sharp correlation inequality
  3. Peter Keevash, On Kahn’s flow conjecture
  4. On Kahn’s flow conjecture
  5. Sharp correlation inequality used in the proof
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