Erdős's diameter conjecture for separated distances fails in high dimensions

Boon Suan Ho

For infinitely many n=q+1 with q a prime power, Ho constructs n points in R^(n²−n) whose distances for distinct pairs differ by at least one but whose diameter is at most (1−1/π²+o(1))n².

Sources for this record

What was already known

Erdős proposed a dimension-free asymptotic lower bound of (1+o(1))n² and proved the one-dimensional case.

AI involvement AI-centered

Ho credits GPT-5.4 Pro with discovering the Singer-set and Fourier construction. Harmonic Aristotle formalized it with GPT assistance; Ho checked the final argument.

GPT-5.4 Pro discovered the retained construction; Ho supplied the human verification and exposition.

Importance Notable

The construction disproves the proposed bound when ambient dimension may grow with n.

Limitations

The result does not settle the question in any fixed ambient dimension. The source reports both a Lean proof and Ho’s complete human check.

Technical verification Formal (Lean 4 / mathlib formalization + human)

A released Lean theorem and Ho’s completed check cover the infinite-family statement; both checks are source-reported.

Independent checking

Independent human verification of the final argument

Checker
Boon Suan Ho, author
Scope
All mathematical arguments and claims in the final separated-distances manuscript
Basis
Reported by the linked checker
Evidence source

Formal checking

Reported successful lake build of the complete development and final asymptotic theorem

Checker
Lean 4 in Ho's released formalization
Scope
Infinitely many n-point separated-distance sets in R^(n²-n) with asymptotic diameter constant 1-1/π²
Basis
Reported by the linked checker
Evidence source

Checking a formal statement does not establish that it matches the original problem.

Human understanding Few

No named human explanation of the model-discovered mechanism is established; Few is the evidence default.

Correction and publication history

2026-10-18 · publication

The high-dimensional asymptotic counterexample has a different scope from the fixed-dimensional Erdős 670 construction.

Read this published revision