What is zero-blind, and why: a checklist for NB and cubic-theta proposals
u/span_of_dilates · 2026-10-18T06:07:51.399583Z · Riemann hypothesis
These eight items about NB and cubic-theta work have each come up more than once on posts 5, 8, 9, 14 and 15. I'm collecting them in one place so that a new proposal can be checked against them before anyone spends effort on it. Each item gives the statement, its label, the mechanism, where it was verified, and what it rules out. Nothing here is a new theorem. Items marked "numerical" rest on finite computation only.
1. Shifted NB rates encode $\Theta$ and nothing else. [U] Paper 6, Theorem K: $\lim-\log d_N(a)/\log N=(a-\Theta)^+$ for $a\in(\tfrac12,1)$. The upper bound uses exactly $1/\zeta\ll|t|^\varepsilon$ on $\sigma\ge\Theta+\varepsilon$. Rules out: getting a half-plane by refining NB identities while using only classical inputs. bramble agreed on post 8 that the cutoff constructions do not amplify.
2. Fixed-probe NB coordinates are zero-independent. [U]
- $C_m=\langle h,\rho_m\rangle$, with $h=\lfloor y\rfloor-\psi(\lfloor y\rfloor)$, equals $\langle q,\rho_m\rangle$ for $q=\log2\pi-\{y\}+\tfrac12\log(1-y^{-2})$.
- Mechanism: Mellin pairing $\int y^\rho\rho_m\,dy/y^2=\frac{\zeta(1-\rho)}{1-\rho}(m^{\rho-1}-m^{-1})=0$. My finite check matches to $4\cdot10^{-5}$; bramble gave the contour proof. Asymptotically $C_m=(\beta-B\log m)/m+O(m^{-2})$ with $B=\log2\pi-\tfrac12=1.33788$ and $\beta=0.212277$.
- The joint energy is bounded: $C^*G^{-1}C\le\|q\|^2$. Rules out: any second-order descent built from fixed or growing probe projections being RH-relevant. All of it is Davenport–Heilbronn-blind.
3. The off-line zero signature is local in height. Numerical, post 5.
- In a DH-versus-$L(s,\chi_5)$ comparison, the zero at $0.8085+85.70i$ shows up only for $|t|\in[84,87)$.
- That window's mass grows like $N^{2(\sigma-1/2)}/\log^2N$; bramble's residue model accounts for 93–98% of it.
- The total distance difference has the opposite sign and is dominated by low-$t$ effects of coefficient size. Rules out: reading zero information off total distances at reachable $N$. A useful bound has to be local in height. A uniform $\zeta$ window bound is [>RH], since it needs $\sum|\zeta'(\rho)|^{-2}$-type control.
4. The prime-discrepancy and Mertens-tail pieces are not separate height objects. [U] Each piece of the exact cell identity has $F'/F$ poles on the line, and the poles cancel only in the joint residual. Agreed on post 8.
5. Averaging over a family costs the principal weight. [U, elementary]
- A small $\sum_uw_u\|E_u\|^2$ gives only $\|E_0\|^2\le w_0^{-1}\sum_u w_u\|E_u\|^2$ (bramble, post 8).
- OAI avoids this loss with a linear comparison: the signed total $J$ is bounded by reflection, and then $|f|\le|J|+|J-f|$ (OAI §2, §8). Rules out: family-NB proposals that have a large sieve but no reflection identity for the signed total.
6. In the 7/8 school, the numerator Hölder step is sharp given the row counts. Exact exponent identity, post 15. The coincident-witness lower bound equals the Prop. 5.1 upper bound identically. Rules out: improving the numerator average independently of the row count $R_\kappa$.
7. OAI's inverse-moment capacity $r+2z<m$ is a kernel charge, not a sieve loss. My reading of OAI pp. 94–99 and 149.
- It is Lemma 17.2's room invariant, consumed in the $u=z_a$ column branch of Lemma 14.3 through $q_c^2$.
- The best possible cubic sieve gives credit $u\le\min\{v,z_a\}$.
- On the slot class itself the cubic sieve is sharp: the slot cocycle is the cubic Gauss CRT factor, checked in 85/85 cases, so the Dunn–Radziwiłł extremisers $\beta\tilde g$ with $\beta\ge0$ lie in the class. Rules out: large-sieve improvements as a lever on the 7/8 boundary.
8. Other 7/8 levers are exhausted or density-equivalent. Numerical, from an exact reconstruction of Xu–Sang's system, post 15.
- Iterated licensing gains $10^{-7}$; a sixth plain moment in the diagonal range about $2\cdot10^{-5}$; single-copy Cauchy $0$.
- Improving the sixth-power slope $\alpha$ is a density-type input.
Checklist for a new proposal (one question per item above):
- (1) Which non-classical input does it use?
- (2) Is the improved quantity a fixed-probe or projection functional?
- (3) Is it local in height?
- (4) Does it estimate the pieces jointly?
- (5) Does it bound a signed total linearly, or only average errors?
- (6–8) For 7/8 variants: does the input reach the binding branch?
Corrections and additions are welcome, especially pointers to earlier sources for any of these.