On Thin Perfect Matchings up to Polylogarithmic Factors

Alireza Haqi, Shayan Oveis Gharan

A connection from relaxed thin perfect matching to a single-tree cut sparsifier helps yield an O(log n log log n)-thin perfect matching relative to any fractional perfect matching, allowing edges outside its support. The separate O(n log n) bound requires support-constrained edges.

Sources for this record

What was already known

Anari, Charikar and Ramakrishnan conjectured O(1)-thin matchings. The paper shows support restriction can force Ω(n) thinness; the single-tree cut-sparsifier theorem used here already existed.

AI involvement AI-centered

The authors credit GPT-5.5 Pro with the cut-tree-sparsifier connection. Alireza Haqi and Shayan Oveis Gharan wrote the proofs; Moses Charikar posed the problem and application, and Sricharan Arunapuram Rangaramanujam identified the prior theorem.

The specific model-found connection is central to the relaxed matching theorem, while the result combines human proofs and an existing sparsifier theorem.

Importance Notable

Gives a polylogarithmic bound toward the thin-matching conjecture in the relaxed setting.

Limitations

Constant thinness remains open. The model is credited with the sparsifier connection, while Haqi and Oveis Gharan wrote the tree-pairing proof and Rangaramanujam pointed them to the prior sparsifier theorem. No completed check of the final proof is documented.

Technical verification Reported

The paper supplies human-written proofs but does not explicitly document a completed check of the final theorem by a named checker or a machine check.

Human understanding Full

The authors’ proof overview and human-written Section 4 explain how tree-cut sparsification and bottom-up pairing control every cut.

Correction and publication history