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Exponent for commutators close to the identity

85a
Upper bound, last-listed row
| $4$ | [Bil26] | Same nonlinear system as [Tao19], with a sharper *point-source Green function* estimate on the right inverse (norm $O(n)$ on scalar point sources, versus $O(n^2)$ in the worst case), proved by interpreting iterated Cuntz block coefficients as a killed walk and comparing them with binomial incidence matrices. This upgrades the fixed-point scale from $\delta \asymp n^{-5}$ to $\delta \asymp n^{-4}$ and improves the exponent from $5$ to $4$. Result and Lean 4 formalization produced autonomously by GPT-5.6 Sol High (13 min for the proof, ${<}3$ h for the formalization). |tracked since 2026-07-24 — no movement seen yet
Lower bound, last-listed row
| $1$ | [Pop82] | Popa's quantitative Wintner–Wielandt bound $m_H(\varepsilon) \ge \tfrac{1}{2}\log(1/\varepsilon)$; see [Tao19, Theorem 0.1] for a short reproduction. Conjectured to be sharp. |tracked since 2026-07-24 — no movement seen yet
Checked against material for its cited source
1 bound row(s) here have been checked against material for their cited source (1 drawn by position, 0 chosen because something already looked wrong). Across this whole ledger 70 row(s) have been drawn by position, against 691 rows that name a source, counted on 2026-09-27: 64 were checked against material for their cited sources and for 6 the cited source could not be read at all. 5 more were chosen for suspicion and checked; they are counted apart, because a set selected for suspicion carries no rate. A row not listed here has NOT been checked.
the mirrored file · upstream source · looks wrong?
Cite this rowBounds Ledger — Exponent for commutators close to the identity (85a) upper bound: $4$ (tracked since 2026-07-24 — no movement seen yet) lower bound: $1$ (tracked since 2026-07-24 — no movement seen yet) Mirrored from teorth/optimizationproblems@2c1968c. These are the last-listed rows of that constant's bounds table — a listing position, not a statement that this bound is the strongest or most recent. A snapshot at that sha, not a live read. https://u00dxk2.github.io/bounds-ledger/c/85a.html