| $\pi/2-\delta$ with $\delta\approx 0.00013$ | [IS2024] | Provides an explicit integral expression for $\delta$ and evaluates it numerically (about $1.3\times 10^{-4}$). |tracked since 2026-07-24 — no movement seen yet
Lower bound, last-listed row
| $\sqrt{\pi/2} \approx 1.25331$ | [Pisier1986], [ILvHV2019] | Comes from the sharp Gaussian $L^1$-Poincaré inequality (Pisier).|tracked since 2026-07-24 — no movement seen yet
Cite this rowBounds Ledger — The $L^1$ Poincaré constant on the Hamming cube (11a)
upper bound: $\pi/2-\delta$ with $\delta\approx 0.00013$ (tracked since 2026-07-24 — no movement seen yet)
lower bound: $\sqrt{\pi/2} \approx 1.25331$ (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/11a.html