Generic Robust Flower Control Still Stops Before Dense Tangle Breadth¶
Claim/Theorem¶
Keep the notation of [[dense-tangle-breadth-is-the-canonical-remaining-intrinsic-target.md]], [[robust-tangle-tree-displays-all-nonsequential-separations.md]], [[every-k-flower-is-anemone-or-daisy.md]], [[k-flower-local-connectivity-classification.md]], [[robust-nonsequentiality-route-stops-before-tangle-orientation-of-balanced-cuts.md]], and [[best-external-near-bridges-still-stop-before-robust-balanced-cut-orientation.md]].
Even if one grants the missing tangle-orientation step for Route B, the generic robust/nonsequential/flower package still stops before dense breadth.
More precisely:
-
Clark--Whittle show that, once a tangle of order
kis robust and the relevantk-separations are already known to be nonsequential with respect to that tangle, those separations are displayed by a single tree up to tangle-equivalence. -
Aikin--Oxley then show that every
k-flower is an anemone or a daisy, and forn\ge 5petals its local connectivity data is controlled by integersc,dsatisfying\[ k-1 \ge c \ge d \ge \max\{2c-(k-1),0\}. \]They also compute the local connectivity between arbitrary unions of petals purely from the arc counts and these parameters.
-
Most importantly for the current frontier, Aikin--Oxley also prove the converse existence theorem: for every admissible parameter pair
(c,d)and every petal countn\ge 3, there exists a matroid with ak-flower having exactly that local-connectivity template. -
Therefore generic flower-side control after orientation imposes no density concentration on the underlying ground set. The data
- “all balanced low-rank cuts lie in one robust flower regime”,
- “the regime is an anemone or daisy”, and
- “its local connectivities are given by admissible
(k,c,d)data”
still does not force dense tangle breadth, a sufficiently dense
k-connected set, or linear balanced cut rank. -
So the exact post-orientation missing theorem on Route B is stronger than the current node [[robust-nonsequentiality-route-stops-before-tangle-orientation-of-balanced-cuts.md]] alone suggests:
\[ H_{\mathrm{flower}}^{\mathrm{dense}}(\beta): \quad \text{in the target family, a } \beta\text{-balanced sublinear-rank cut cannot persist inside an admissible robust flower template} \]unless that template already yields dense original-matroid concentration.
Equivalently, once balanced low-rank cuts have been oriented into one robust tangle, the remaining gap is not generic flower classification. It is a family-specific petal-mass exclusion or concentration theorem.
Therefore Route B is now sharper in a stronger sense:
even after the missing orientation theorem
H_{\mathrm{ns}}^{\beta}, generic robust flower theory is still too permissive to close the dense-breadth frontier.
Dependencies¶
- [[dense-tangle-breadth-is-the-canonical-remaining-intrinsic-target.md]]
- [[robust-tangle-tree-displays-all-nonsequential-separations.md]]
- [[every-k-flower-is-anemone-or-daisy.md]]
- [[k-flower-local-connectivity-classification.md]]
- [[robust-nonsequentiality-route-stops-before-tangle-orientation-of-balanced-cuts.md]]
- [[best-external-near-bridges-still-stop-before-robust-balanced-cut-orientation.md]]
Conflicts/Gaps¶
- This node does not prove that
H_{\mathrm{ns}}^{\beta}is false; it sharpens what would still be missing after that theorem. - It does not show that the target Quantum Tanner / left-right-Cayley family realizes any such flower obstruction. The point is that generic flower theory by itself does not rule the obstruction out.
- A future family-specific theorem excluding admissible robust flower templates on hardware-balanced cuts would reopen Route B.
Sources¶
10.1016/j.jctb.2013.03.00210.1016/j.aam.2007.05.004