Entropy bounds for perfect matchings with prescribed marginals

For a loopless multigraph on 2m vertices and feasible edge marginals x, let H(x) be the largest entropy of a random perfect matching with those marginals. How accurately can H(x) be estimated by coordinate-entropy expressions?

Why it matters and what counts as progress

Why it matters: An error linear in the number of vertices would extend useful convex estimates from bipartite to general-graph perfect matchings.

What counts as progress: A uniform linear-error estimate for every feasible x, with the entropy terms and graph assumptions stated, or an example violating it.

How the problem developed

  1. 2 Jul 2018 · Framework [1]

    Nima Anari, Shayan Oveis Gharan and Cynthia Vinzant Developed a log-concave polynomial and entropy framework for counting matroid bases, providing background for later entropy questions about matching laws.

  2. 23 Sept 2026 · Reported claim [2]

    OpenAI internal model The preprint claims a sharp pointwise entropy inequality at every feasible edge-marginal vector for loopless labelled multigraphs, including boundary points, and also determines matching-polytope face dimensions.

AI contribution

Entropy and Face Dimension of the Perfect-Matching Polytope

OpenAI

For a loopless multigraph on 2m vertices with a perfect matching and feasible edge marginals x, the maximum entropy H(x) satisfies F(x)−(2−2/m)B(x)≤H(x)≤F(x), where F and B sum the binary-coordinate entropy terms. Optimizing gives the linear-error estimate proposed by Anari, Oveis Gharan and Vinzant.

AI involvementAI-led
ImportanceNotable
Technical verificationReported
Human understandingFew
Reported

Sources

  1. Anari, Oveis Gharan and Vinzant, Log-Concave Polynomials I: Entropy and a Deterministic Approximation Algorithm for Counting Bases of Matroids
  2. OpenAI, Entropy and Face Dimension of the Perfect-Matching Polytope
  3. Entropy and Face Dimension of the Perfect-Matching Polytope
  4. OpenAI perfect-matching entropy manuscript
  5. Exact pointwise entropy comparator
  6. Lean proof of a weaker matching bound
  7. Anari–Oveis Gharan–Vinzant entropy framework
  8. OpenAI mathematics release account
Website timeline

Publication dates and editorial changes.