master-equation
Status and infobox
- status:
—→ proved - tier:
—→ V4 - kind:
—→ theorem - year:
—→ 2026 - statement:
—→ For a torus-equivariant twisted lift $G=(m\tilde g,\,m^2\tilde h)$ on the invariants, the Jacobian is constant if and only if $m\{\tilde g,\tilde h\}+2\tilde h\{\tilde g,m\}+\tilde g\{m,\tilde h\}=c\neq0$. - short:
—→ Constant Jacobian of a torus-equivariant lift ⇔ one bracket identity downstairs
Relations
- + related to graded-equivariant-keller: Shaska derives the same order-two vanishing on the contracted locus independently, as a bracket identity on the quotient (Thm 8.3). The equation is the tool behind the plane wall for torus-symmetric maps.
Source +25 −0
Revision 269 as rendered
Alpöge's map is equivariant for the torus, so it is determined by what it does on the invariants and . On 20 July 2026 the Fong–Fable session computed that descent, as follows.[1]
- The products and are invariant.
- With , , , and , they equal and .
- The constant Jacobian upstairs becomes a single identity in the Poisson bracket , with constant .
The atlas re-checks all three identities exactly on every view:
Alpöge’s map descends to the invariants t = xy, w = x²z, and there its constant Jacobian becomes one bracket identity with constant 2 (the master equation of the Fong–Fable ledger).
- ✓ F₂F₃ = m·g̃ with t = xy, w = x²z polynomial identity in x, y, z, exact
- ✓ F₁F₃² = m²·h̃ polynomial identity in x, y, z, exact
- ✓ m{g̃,h̃} + 2h̃{g̃,m} + g̃{m,h̃} is the constant 2 the bracket expression = 2
GET /api/check/master-equation.The ledger reports the same identity for Gallagher's , with , and for the factory's branch N2. The atlas has not re-checked those two. The general equivalence is a chain-rule computation through the descent. It is unrefereed, hence V4. Shaska derives the same order-two vanishing on the contracted locus independently, as a bracket identity on the quotient (Thm 8.3).[2] The equation is the tool behind the plane wall for torus-symmetric maps. In two variables the torus has a one-dimensional invariant ring, the equation degenerates to , and only affine maps survive.
It is also the setting of the ledger's open question O4: quantize the master equation to get an explicit non-surjective endomorphism of the Weyl algebra . An explicit one already exists by the classical pullback (see DCₙ).
- ↑ D. Fong and Claude Fable 5, claims ledger, entry C5 and theorem 5 of the theorems register.
- ↑ T. Shaska, Graded Keller maps and the Jacobian Conjecture, Theorem 8.3.