Stable sheets in four dimensions

Four zipper families in exterior parameters   |c₁|, |c₂| > 1

0.500
Fourth coordinate shown by color
Drag to rotate · Scroll to zoom · Arrow keys to rotateCertified stable patches · Upper and lower q half-planes
w = 0w = 1Relative contraction weight

Each sheet approximates the nonlinear image of a certified inner cover with a triangular mesh. Color and the weight filter retain the fourth coordinate w; the three-dimensional view projects it out. Blank space carries no classification. Apparent intersections between projected sheets need not be intersections in four dimensions.

Coordinates of this earlier coefficient-phase projection

This September viewer retains its original projection. The mirror contact atlas and 4D explorer use the manuscript’s (ρ, α, γ) chart. The zipper indices describe traversal choices, separately from map orientation.

c₁ = 1/a, c₂ = 1/b;   ρ = 2/(|a|+|b|);   w = |a|/(|a|+|b|).
θ₁ = arg(a), θ₂ = arg(b).
X = (4 + ρ cos θ₁) cos θ₂
Y = (4 + ρ cos θ₁) sin θ₂
Z = ρ sin θ₁

At fixed w and orientation, this chart is injective on the displayed range 0 < ρ ≤ 2. Direct and mixed systems belong to separate orientation charts. Its central hole comes from the display map. The faint grid is the reference torus ρ = 2. The slider selects a finite band w ± 0.025 around the centres of displayed cells.

Three probes, four families

Select a curve to locate it
A ½ + ⅕ iB ½ + ⅖ iC Island probe

Curve branches are red and blue where a stable certificate is available. The two neutral C examples are included for comparison; they are not part of the displayed stable sheets. These polygonal drawings have a uniform error bound below 0.0051 in the endpoint coordinate.