Discrete geometry · Combinatorics · Conjecture

Erdős unit-distance problem

Is the maximum number of unit-distance pairs among n distinct planar points bounded by n1+o(1)n^{1+o(1)} as n grows?

DisprovedOpenMath assessment · Oct 13, 2026

Earlier version 2 of this page. View current →

Overview

Known

A fixed positive power gain refutes the near-linear Euclidean conjecture in the cited proof and human companion exposition. Exact extremal growth remains a related research question.

Latest

Precise statement

Count unordered pairs of distinct points in the Euclidean plane at distance exactly one. Write u(n) for the maximum over all n-point sets. The conjecture asks that for every ε > 0, u(n) ≤ n^(1+ε) for all sufficiently large n. Determining the exact extremal growth remains a broader question.

Question paraphrased by OpenMath. Original wording is available in the sources.

Landscape

Figures and explorable examples. Selecting a statement opens its exact wording.

Where the growth exponent lies

The true exponent θ is now known to lie strictly above 1 and at most 4/3. The 2026 gain δ is not explicit, so the open interval is drawn from 1, which is itself excluded. Erdős’s grid gives a gain c/log log n that tends to zero, which is why the conjecture θ = 1 was plausible.

11.11.24/3exponent θOpenthe true exponent, now known toexceed 1Targetθ = 1, Erdős’s conjecture, refutedProvedθ ≤ 4/3(Spencer–Szemerédi–Trotter)

Visual setup

What counts as one unit-distance pair?

A unit square has four distance-one pairs; its diagonals are longer. Each unordered pair is counted once.

Reading boundary. A drawing of four points does not demonstrate a fixed exponent gain or the asymptotic counterexample.

What counts as one unit-distance pair?Four corner points form a square with its four sides highlighted. A dashed diagonal is excluded from the unit-pair count. This finite example introduces the quantity used in the asymptotic theorem.Distance 1√24 points · 4 unit pairs

The square illustrates counting only. Select a statement for its exact scope and sources.

Text version

Four corner points form a square with its four sides highlighted. A dashed diagonal is excluded from the unit-pair count. This finite example introduces the quantity used in the asymptotic theorem.

The mathematical example is a unit square; the drawing coordinates are illustrative. Only distinct unordered Euclidean distance-one pairs count.

  1. Read the counting convention

    Disproved

    The near-linear unit-distance conjecture

    The near-linear asymptotic assertion is refuted; this does not determine the exact maximum.

    The near-linear unit-distance conjecture →

  2. Read the asymptotic counterexample

    Proved

    A fixed power gain for infinitely many sizes

    An asymptotic construction, not a statement about every size or an explicit value of δ.

    A fixed power gain for infinitely many sizes →

Sources & review

Authored by OpenMath source curation on 2026-10-13 (AI-assisted curation). Independent review of this visual explanation is pending; linked assertions and relationships have their own assessments.

Results

The question 1

Counterexamples 1

Related advances 1

  • Proved
    The classical upper bound

    The classical incidence bound limits all finite point sets.

    Alon et al. 2026

Connections

Consequences 1

Assuming A fixed power gain for infinitely many sizesProved

Approaches

How the problem is attacked, and what each line of attack cannot yet reach.

Arithmetic creates many unit-length differences

The argument uses growing number fields, norm-one elements and a lattice window to create many planar distance-one pairs.

Cannot yet reach The four-point illustration is not the arithmetic construction or its proof.

Sources & review

Supporting statements

Source-grounded explanation · independent explanation review: pending.

Timeline

  1. A pinned Euclidean Lean submissionFormalization

    The repository supplies an exact theorem for the fixed exponent gain.

    The revision date is not the discovery date; OpenMath has not built the project.

  2. Erdős problem #90Formalization

    Formalization of an existing proof. Contribution type: Formalization.

  3. Erdős problem #90New proof

    Full solution. Contribution type: AI standalone.

  4. A model-generated construction refutes near-linear growthRelated result

    OpenAI releases the proof with a human companion argument.

    Discovery, exposition and later numerical exponent improvements have different credits.

  5. A universal four-thirds upper boundBound established

    Spencer, Szemerédi and Trotter establish the classical incidence estimate.

    An upper bound does not exhibit configurations attaining it.

  6. Erdős introduces the planar distance questionFoundation

    The original point-pair question has an elementary formulation but an asymptotic target.

    Unit distances and distinct distances are different extremal questions.

Full history with sources →

Evidence

Evidence by kind
Literature

2 preprints · 3 projects

Status OpenMath assessment · Oct 13, 2026.

Formal

1 complete proof

1 formalization below ↓

Reported in sources: A pinned Lean submission reports the asymptotic counterexample with exact Euclidean pair counting. External execution and independent OpenMath review remain pending.

Computation

None recorded

Review

Not yet reviewed

OpenMath assessment: A fixed positive power gain refutes the near-linear Euclidean conjecture in the cited proof and human companion exposition. Exact extremal growth remains a related research question.

Source comparison and reader curation; independent mathematical assessment remains pending.

OpenMath pilot collection · OpenMath source curation · assessed Oct 13, 2026 · review due Jan 13, 2027

Collection last checked Oct 13, 2026.

Formalizations

A fixed power gain for infinitely many sizes →

External proof reports do not establish an OpenMath run, independent statement correspondence, or independent mathematical review.

Sources

Choose a starting point below. Each result links to its exact statement, cited passages and checks.

Start here

Bibliography 5

Research activity · 1 entry

Contributions

OpenAI’s unnamed internal model generated the original construction. The nine companion-paper authors provide human exposition and checking; Will Sawin’s announced exponent refinement has separate credit. The plby/Erdos90 project supplies the linked formal submission; its checked README does not identify an individual formalization author.

Selected literature; source observations and coverage limits are retained in the publication details.

Record details
Record version
2
Classification
MSC2020 52C10 / 05D99
Prerequisite level
undergraduate
Source observations & version history →