Algebraic geometry · Conjecture

Jacobian conjecture

Must every polynomial map F: Cn\mathbb C^n → ℂⁿ with a constant nonzero Jacobian determinant have a polynomial inverse?

DisprovedOpenMath assessment · Oct 13, 2026

Earlier version 4 of this page. View current →

Overview

Known

The cited explicit three-variable witness refutes the universal complex formulation. Its determinant and colliding rational inputs are exposed as separate, inspectable evidence.

Latest

Precise statement

Complex polynomial maps in finite dimension n ≥ 1. A local derivative condition is being compared with global polynomial invertibility; the two-variable restriction is a separate question.

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

Landscape

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

Check the counterexample

Exact rational arithmetic: the three inputs have the same image, and the Jacobian determinant is the constant −2. A polynomial inverse would make F injective, so none exists.

Input (x, y, z)F(x, y, z)det JF there
(0, 0, −1/4)(−1/4, 0, 0)−2
(1, −3/2, 13/2)(−1/4, 0, 0)−2
(−1, 3/2, 13/2)(−1/4, 0, 0)−2
All (x, y, z)—−2 (expands to a constant)

This checks the stated witness by direct computation. It says nothing about two variables, where the question is open.

Visual setup

Three inputs, one image

The displayed rational points have the same image under the explicit map F. Segments indicate mapping, not paths in ℂ³.

Reading boundary. The layout is symbolic; it is not a projection of the six-real-dimensional domain. It says nothing about the two-variable case.

Three inputs, one imageThree input points (0,0,−1/4), (1,−3/2,13/2) and (−1,3/2,13/2) map to (−1/4,0,0), despite det JF = −2.Three distinct inputsOne outputdet JF = −2(0, 0, −1/4)(1, −3/2, 13/2)(−1, 3/2, 13/2)(−1/4, 0, 0)

Select a statement below for its scope and evidence. The text view describes the complete drawing.

Text version

Three input points (0,0,−1/4), (1,−3/2,13/2) and (−1,3/2,13/2) map to (−1/4,0,0), despite det JF = −2.

Coordinates in the drawing are illustrative unless the caption specifies an exact example.

  1. Inspect the counterexample

    Proved

    A constant determinant with three inputs sharing an output

    A concrete failure of injectivity and hence of a polynomial inverse. The coordinate degrees are 7, 6 and 4; a cubic fiber relation does not make this a cubic coordinate map.

    A constant determinant with three inputs sharing an output →

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

Variants and analogues 1

Background 1

  • Proved
    No polynomial inverse for the three-variable witness

    The source witnesses this existence statement using the three-variable counterexample.

    alerad/alpoge-lean project 2026Formalized

Connections

Analogues and related questions 1

Consequences 1

Assuming A constant determinant with three inputs sharing an outputProved

Approaches

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

Check a witness instead of a universal obstruction

The counterexample can be inspected through exact polynomial differentiation and substitution of three rational inputs.

Cannot yet reach A determinant calculation alone would not demonstrate failure of global inversion.

Sources & review

Supporting statements

Source-grounded explanation · independent explanation review: pending.

Timeline

  1. Separate algebraic analysisAssessment

    Shuhong Gao analyzes the counterexample and its algebraic structure.

    This is a separate contribution, not the original discovery.

  2. Polynomial counterexample formalizedFormalization

    A public Lean revision proves the determinant, fiber collision and failure of polynomial inversion.

    A source build report is not an OpenMath execution; analytic identification is outside the formal scope.

  3. Explicit three-variable counterexampleProposal

    The cited manuscript records Alpöge’s announcement, Mathew’s question and Fable’s contribution to finding the displayed witness.

    Credits concern discovery; independent OpenMath mathematical review is pending.

  4. Keller’s global invertibility questionFoundation

    The classical question asks whether a constant nonzero polynomial Jacobian forces global polynomial invertibility.

    The question depends on the field and dimension.

Full history with sources →

Evidence

Evidence by kind
Literature

2 preprints · 1 project

Status OpenMath assessment · Oct 13, 2026.

Formal

2 complete proofs

2 formalizations below ↓

Reported in sources: Formal polynomial determinant, fiber collision and no-inverse results have public pinned Lean sources. Analytic derivative correspondence is outside their stated scope; no local proof build is recorded.

Computation

None recorded

Review

Not yet reviewed

OpenMath assessment: The cited explicit three-variable witness refutes the universal complex formulation. Its determinant and colliding rational inputs are exposed as separate, inspectable evidence.

Source comparison and page curation only; independent mathematical review is pending.

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

Collection last checked Oct 13, 2026.

Formalizations

A constant determinant with three inputs sharing an output →

No polynomial inverse for the three-variable witness →

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 3

Research activity · 1 entry

Contributions

The discovery report credits Levent Alpöge, Akhil Mathew for asking the question and Fable for work leading to the example. The July 20 ULAM verification manuscript prints no author name. Separate analysis: Shuhong Gao. Formalization: the alerad/alpoge-lean project’s reported AI-assisted workflow.

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

Record details
Record version
4
Classification
MSC2020 14R15 / 14R10
Prerequisite level
graduate
Source observations & version history →