Algebraic geometry

An explicit noncoordinate polynomial with affine three-space zero fibre

A polynomial zero fibre and an ambient coordinate obstruction

6 pages3 claims indexed13 referencesManuscript 2026-09-24

The proposed argument

The manuscript defines a polynomial from a cusp relation and a shifted auxiliary algebra. A local lifting lemma identifies its zero-fibre quotient with a polynomial extension of a two-variable ring. An ambient polynomial identity supplies a critical point on another fibre, and a Jacobian argument is used to rule out a coordinate. Adjoining variables gives the higher-dimensional statements; the appendix records both coordinate maps.

The reading guide describes the manuscript’s argument. Independent human assessment remains pending. Review assessments and source checks are available separately. The appendix is Appendix A in the PDF; the source map preserves its native label app:coordinates.

Reading order

  1. 01

    Define the construction and scope

    Introduce the cusp polynomials and the coordinate/zero-fibre distinction.

  2. 02

    Establish the lifting parameter

    Replace the cusp presentation by a single free polynomial parameter over the base ring.

  3. 03

    Identify the fibre and apply the obstruction

    Combine the base-algebra shift with lifting and the ambient critical-point identity.

  4. 04

    Record explicit coordinate maps

    Give the forward map, inverse map and Bezout certificate.

Follow the dependencies

Open the full map ↗

Select a claim to see its prerequisites and consumers. Edge labels distinguish proof inputs, source references, background and exclusions.

Your independent assessment

Reconstruct the base-ring parametrization and the lifting lemma. Check both polynomial inverse maps, the unit-ideal identity and the ambient critical-point obstruction. Keep the zero-fibre calculation distinct from the behavior of other fibres.

Notes stay on this device.