Bernoulli-2 Farey Large-Sieve Neutral Descent and Supercritical Truncated Divisor Covariance

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Abstract

We establish two unconditional theorems on multi-probe Selberg-Mobius approximation in the Nyman-Beurling Hilbert space and supercritical truncated divisor sums. First (Theorem 1), for the codimension-2 neutral subspace $W_K$ of [1], we prove that the periodic quadratic wave $b_m(k)$ satisfies the exact forward-difference identity $b_m(k+1)-b_m(k)=-f_m(k)$ at every integer $k\ge 1$ and has closed-form GCD correlation $R_{m,n}$ vanishing whenever $\gcd(m,n)=1$. Using the sharp all-$d$ majorant $\phi_4^{(B)}(d)\le (45/16)d^4$, Weighted Schur's Test on the divisor-jump matrix ($ \sup(c^{\mathsf{T}}R_K c)^{1/2}/\|u\|_{\mathcal{H}}\le (\sqrt{2\zeta(3)}/8)K^2(1+\log K)^{3/2}$), and the Montgomery-Vaughan Hilbert inequality on the Farey set $\mathcal{F}_K$, we prove $\|P_{W_K}((\log N)(1-g_N)-q)\|_{\mathcal{H}}\ll K^2(\log K)^{3/2}(\log N)^{3/2}/N$ for all $2\le K\le N^{1/2}$, improving [1]'s bound by $K^{1/2}(\log K)^{-3/2}(\log N)^{-3/2}$ and extending unconditional neutral descent to $K\le N^{1/2-\varepsilon}$. Second (Theorem 2), building on the supercritical divisor-complementation sieve of de la Breteche, Dress, and Tenenbaum [2] and going beyond the $O(N)$ supercritical second moment of Graham [3], we establish the unequal-cutoff covariance profile $\mathcal{D}_2(N/X_1,N/X_2)$ and the explicit Goldston-Yildirim mean-square error profile $\mathcal{L}_2(N/X_1)$ for $N^{1/2}<X_1\le X_2\le N$, retaining the $(g,u_1,u_2)$-dependent logarithmic Stieltjes weight via Tonelli integration to prove uniform $O(N^{-1/2}Y_1(\log(2Y_1))^2)$ remainders. No bound on the leading residual norm of $1-g_N$, off-diagonal shift correlation, or proof of RH is claimed.

Bernoulli-2 Farey Large-Sieve Neutral Descent and Supercritical Truncated Divisor Covariance

Abstract

We establish two unconditional theorems on multi-probe Selberg–Möbius approximation in the Nyman–Beurling Hilbert space $\mathcal{H} = L^2((1, \infty), y^{-2}\,dy)$ and on supercritical truncated divisor sums:

  1. Bernoulli-2 Farey Large-Sieve Neutral Descent (Theorem 1): In [1], the codimension-2 neutral subspace $W_K = \{u = \sum_{m=2}^K c_m\rho_m : \sum_{m=2}^K c_m a_m = \sum_{m=2}^K c_m T_m(1) = 0\}$ was shown to eliminate the slow harmonic moment terms identically, giving a zero-free-region-free tail identity and the $L^1$ triangle-inequality bound $\|P_{W_K}((\log N)(1 - g_N) - q)\|_{\mathcal{H}} \ll K^{5/2}/N$ for $K \le N^{2/5-\varepsilon}$. We prove that the quadratic wave $b_m(k) := \frac{m^2 - 1 - 6r(m - r)}{12m}$ ($r = k \bmod m$) has zero discrete period sum $\sum_{r=0}^{m-1} b_m(r) \equiv 0$ and satisfies the exact forward-difference identity $b_m(k+1) - b_m(k) \equiv -f_m(k) = -(\rho_m(k) + a_m)$ at every integer node $k \ge 1$, giving by summation by parts the exact kernel decomposition $K_m(k) \equiv \frac{b_m(k)}{k(k+1)} - 2\sum_{j=k+1}^\infty \frac{b_m(j)}{(j-1)j(j+1)}$. Over common periods $\operatorname{lcm}(m, n)$, $b_m(k)$ and $b_n(k)$ have the closed-form GCD correlation $R_{m, n} \equiv \frac{(\gcd(m, n)^2 - 1)(\gcd(m, n)^2 + 11)}{720 m n}$, which vanishes whenever $\gcd(m, n) = 1$. Using the sharp all-$d$ majorant $\phi_4^{(B)}(d) \le (d^2 - 1)(d^2 + 11) \le \frac{45}{16}d^4$ ($d \ge 2$, with equality at $d = 2$) and Weighted Schur's Test ($p_d = d, q_b = 1$) on the divisor-jump matrix $M_{d, b}$, we prove the explicit universal operator bound $$\sup_{u \in V_K \setminus \{0\}} \frac{\bigl(c^{\mathsf{T}} R_K c\bigr)^{1/2}}{\|u\|_{\mathcal{H}}} \;\le\; \frac{\sqrt{2\zeta(3)}}{8}\,K^2\,(1 + \log K)^{3/2} \;\ll\; K^2 (\log K)^{3/2} \qquad (\forall K \ge 2).$$ Combining this with the Montgomery–Vaughan Hilbert inequality [4] on the Farey set $\mathcal{F}_K$ across dyadic blocks $k \in (M, 2M]$, we prove unconditionally that $$\left\|P_{W_K}\bigl((\log N)(1 - g_N) - q\bigr)\right\|_{\mathcal{H}} \;\ll\; \frac{K^2 (\log K)^{3/2} (\log N)^{3/2}}{N} \qquad (\forall\, 2 \le K \le N^{1/2}),$$ improving the bound of [1] by a factor of $K^{1/2}(\log K)^{-3/2}(\log N)^{-3/2}$ and extending the unconditional polynomial range of neutral Selberg–Möbius descent from $K \le N^{2/5-\varepsilon}$ to $K \le N^{1/2-\varepsilon}$.
  2. Uniform Supercritical Two-Cutoff Covariance & Explicit Goldston–Yıldırım Profile (Theorem 2): Using the divisor-complementation and squarefree-coprime sieve mechanism of de la Bretèche, Dress, and Tenenbaum [2, §2] and going beyond the $O(N)$ supercritical second-moment estimate of Graham [3] (see Goldston and Yıldırım [6, §5]), we establish the explicit unequal-cutoff covariance profile $\mathcal{D}_2(Y_1, Y_2)$ and the explicit supercritical Goldston–Yıldırım mean-square error profile $\mathcal{L}_2(Y_1)$ with uniform error bounds:
    • $\frac{1}{N}\sum_{N < n \le 2N} c_{X_1}(n) c_{X_2}(n) = \mathcal{D}_2(N/X_1, N/X_2) + O\bigl(N^{-1/2}\sqrt{Y_1 Y_2}\,(\log(2Y_1))^2\bigr)$ uniformly for all $N^{1/2} < X_1 \le X_2 \le N$ ($Y_i := N/X_i$), and
    • $\frac{1}{N}\sum_{N < n \le 2N}(\Lambda_{X_1}(n) - \Lambda(n))^2 = \mathcal{L}_2(N/X_1) + O\bigl(N^{-1/2} Y_1 (\log(2Y_1))^2\bigr)$ uniformly for all $N^{1/2} < X_1 \le N$, where the dependence of the logarithmic Stieltjes weight $W(t) = \log(u_2 t / X_1)\log(u_1 t / X_1)$ on $(g, u_1, u_2)$ is retained via Tonelli integration to avoid losing two logarithmic powers.

No bound on the leading residual norm $\|1 - g_N\|_{\mathcal{H}}^2$, off-diagonal shift correlation, or proof of the Riemann Hypothesis is claimed.


1. Introduction and Comparison with Prior Literature

In the Nyman–Beurling formulation of the Riemann Hypothesis [10, 9, 8, 7], the Hilbert space $\mathcal{H} := L^2((1, \infty), y^{-2}\,dy)$ carries the uncentered fractional-part generators $$\rho_m(y) \;:=\; \left\lfloor \frac{y}{m} \right\rfloor - \frac{\lfloor y \rfloor}{m} \;=\; -\frac{\lfloor y \rfloor \bmod m}{m} \qquad (m \ge 2),$$ with centered counterparts $f_m(y) := \rho_m(y) + a_m$ where $a_m := \frac{m-1}{2m}$. For the anchored Selberg–Möbius approximant $g_N(y) := \sum_{n=2}^N \mu(n)\bigl(1 - \frac{\log n}{\log N}\bigr)\rho_n(y)$, it was shown in [1] that for any fixed $m \ge 2$, $\langle 1 - g_N, \rho_m \rangle_{\mathcal{H}} = \frac{C_m}{\log N} + O_m((\log N)^{-B})$, where $q(y) := \log(2\pi) - \{y\} + \frac{1}{2}\log(1 - y^{-2}) \in \mathcal{H}$ and $C_m := \langle q, \rho_m \rangle_{\mathcal{H}}$. Moreover, [11, Theorem 2(c) and Theorem 4(d)] decomposed the single-coordinate inner product into harmonic and tail terms and established the unit-step subspace ceiling $\|P_{\mathcal{S}_{\mathrm{step}}} q\|_{\mathcal{H}}^2 \approx 1.27905 < \|q\|_{\mathcal{H}}^2 \approx 1.36543$.

Recently, [1, Section 7] introduced the codimension-2 neutral subspace $$W_K \;:=\; \left\{u = \sum_{m=2}^K c_m\rho_m \in V_K \;:\; \sum_{m=2}^K c_m a_m = 0,\;\; \sum_{m=2}^K c_m T_m(1) = 0\right\} \qquad (K \ge 4),$$ where $T_m(n) := \sum_{j=1}^\infty K_m(jn)$ and $K_m(k) := \int_k^\infty f_m(y)\,y^{-2}\,dy$. Note that whereas Ehm [12, §§8.1–8.2] studied Gram decompositions, Möbius inversion, and moment-adjusted Selberg approximant coefficients $\xi_n$, the construction in [1] and the present paper leaves the anchored approximant $g_N$ untouched and imposes neutrality on the observation probe $u \in W_K$. On $W_K$, both harmonic terms $\frac{a_m\log n - T_m(1)}{n}$ in $G(n, m) = \langle \rho_n, \rho_m \rangle_{\mathcal{H}}$ vanish identically at every integer $n \ge 2$, and $-\sum_{k=2}^\infty K_u(k) = K_u(1) = -\sum_{m=2}^K c_m\frac{\log m}{m} \equiv \langle 1, u \rangle_{\mathcal{H}}$ cancels the $d = 1$ divisor term identically, leaving the exact finite-$N$ tail identity [1, Proposition 6] $$\langle 1 - g_N, u \rangle_{\mathcal{H}} \;-\; \frac{\langle q, u \rangle_{\mathcal{H}}}{\log N} \;\equiv\; -\frac{1}{\log N}\sum_{k = N+1}^\infty \bigl(\Lambda_N(k) - \Lambda(k)\bigr)\,K_u(k) \;\equiv\; \sum_{n > N} \mu(n)\left(1 - \frac{\log n}{\log N}\right) T_u(n),$$ where $\Lambda_N(k) := \sum_{d \mid k, d \le N}\mu(d)\log(N/d)$. Using unit-step jump inversion $c_m = \sum_{b \mid m}\mu(m/b)\Delta u_b$ [1, Eq. (39)] and the pointwise $L^1$ triangle inequality $|K_u(k)| \le \frac{1}{8k^2}\sum_{m=2}^K m|c_m| \ll \frac{K^{5/2}}{k^2}\|u\|_{\mathcal{H}}$, [1, Theorem 7] proved the uniform bound $$\left\|P_{W_K}\bigl((\log N)(1 - g_N) - q\bigr)\right\|_{\mathcal{H}} \;\le\; C\,\frac{K^{5/2}}{N},$$ permitting polynomial growth up to $K = \lfloor N^{2/5-\varepsilon} \rfloor$ with zero appeal to any zero-free region of $\zeta(s)$.

Contributions of This Paper

  1. Beating the $K^{5/2}/N$ Bound via Bernoulli-2 Farey Large Sieve and Weighted Schur's Test (Theorem 1): The $K^{5/2}$ factor in [1] stems from bounding $|K_u(k)|$ by the $L^1$ sum of amplitudes $\sum_{m=2}^K m|c_m|$, which ignores phase cancellation among the periodic waves $K_m(k)$ across different periods $m \le K$. In Theorem 1, we prove that the leading wave $b_m(k) := \frac{m^2 - 1 - 6r(m - r)}{12m}$ ($r = k \bmod m$) has identically zero discrete mean over every period and satisfies the exact forward-difference identity $b_m(k+1) - b_m(k) \equiv -f_m(k)$ across all integer nodes $k \ge 1$, converting the kernel into the exact summation-by-parts decomposition $K_m(k) \equiv \frac{b_m(k)}{k(k+1)} - 2\sum_{j>k}\frac{b_m(j)}{(j-1)j(j+1)}$ with zero remainder. We prove that $b_m(k)$ and $b_n(k)$ have the exact closed-form GCD correlation $R_{m, n} \equiv \frac{(\gcd(m, n)^2 - 1)(\gcd(m, n)^2 + 11)}{720 m n}$ (vanishing whenever $\gcd(m, n) = 1$). Using the sharp all-$d$ bound $\phi_4^{(B)}(d) \le (d^2 - 1)(d^2 + 11) \le \frac{45}{16} d^4$ ($d \ge 2$) and Weighted Schur's Test ($p_d = d, q_b = 1$), we prove that the $L^2$ tail operator norm satisfies $\sup_{u \in V_K \setminus \{0\}} \frac{(c^{\mathsf{T}} R_K c)^{1/2}}{\|u\|_{\mathcal{H}}} \le \frac{\sqrt{2\zeta(3)}}{8} K^2(1 + \log K)^{3/2}$ for all $K \ge 2$. Applying the Montgomery–Vaughan Hilbert inequality [4] on the Farey set $\mathcal{F}_K$ across dyadic blocks $k \in (M, 2M]$, we prove unconditionally: $$\left\|P_{W_K}\bigl((\log N)(1 - g_N) - q\bigr)\right\|_{\mathcal{H}} \;\ll\; \frac{K^2 (\log K)^{3/2} (\log N)^{3/2}}{N} \qquad (\forall\, 2 \le K \le N^{1/2}),$$ improving the bound of [1] by a factor of $K^{1/2}(\log K)^{-3/2}(\log N)^{-3/2}$ and extending the permissible cutoff range to $K \le N^{1/2-\varepsilon}$.
  2. Uniform Supercritical Two-Cutoff Covariance and Explicit Goldston–Yıldırım Profile (Theorem 2): For the truncated Möbius divisor sum $c_X(n) := \sum_{d \mid n, d \le X}\mu(d)$, Dress, Iwaniec, and Tenenbaum [5] proved $\sum_{n \le x} c_z(n)^2 = \frac{6}{\pi^2}x + O(x(\log z)^{-A})$ for $z \le x^{1/2}$, and de la Bretèche, Dress, and Tenenbaum [2, §§1–2] used divisor complementation $m = n/d$ and squarefree-coprime counting to evaluate the single-cutoff supercritical variance $\sum_{n \le x} c_z(n)^2$ for $z > x^{1/2}$. For the truncated von Mangoldt sum $\Lambda_R(n) := \sum_{d \mid n, d \le R}\mu(d)\log(R/d)$, Graham [3] proved $\sum_{n \le N}\Lambda_R(n)^2 = N\log R + O(N)$ across the entire range $1 \le R \le N$ (removing the $O(R^2)$ error, as noted by Goldston and Yıldırım [6, §5, immediately after Theorem 5.1]). In the supercritical regime $X_1 > N^{1/2}$ ($Y_1 := N/X_1 < N^{1/2}$), where $\Lambda_{X_1}(p) = \log X_1$ on primes $p \in (N, 2N]$ so that $(\Lambda_{X_1}(p) - \Lambda(p))^2 = (\log(p/X_1))^2 \asymp (\log Y_1)^2$ is absorbed into Graham's $O(N)$ term when $Y_1$ is bounded, Theorem 2 establishes: (i) the explicit unequal-cutoff supercritical covariance profile $\mathcal{D}_2(Y_1, Y_2)$ with uniform remainder $O\bigl(N^{-1/2}\sqrt{Y_1 Y_2}\,(\log(2Y_1))^2\bigr)$, and (ii) the explicit supercritical Goldston–Yıldırım mean-square error profile $\mathcal{L}_2(Y_1)$ (isolating the exact order-1 coefficient beyond Graham's $O(N)$ bound) with uniform remainder $O\bigl(N^{-1/2} Y_1 (\log(2Y_1))^2\bigr)$ by retaining the $(g, u_1, u_2)$-dependence of the logarithmic Stieltjes weight via Tonelli integration.

2. Bernoulli-2 Farey Large-Sieve Neutral Descent

2.1 Exact Discrete-Mean-Zero Antiderivative, Weighted Schur Test, and Large-Sieve Bound

For every integer $m \ge 2$, let $\rho_m(y) = -(\lfloor y \rfloor \bmod m)/m$, $a_m = \frac{m-1}{2m}$, $f_m(y) = \rho_m(y) + a_m$, and $K_m(k) = \int_k^\infty f_m(y)\,y^{-2}\,dy = \sum_{j=k}^\infty \frac{f_m(j)}{j(j+1)}$. For every integer $k \ge 1$, put $r := k \bmod m \in \{0, 1, \dots, m-1\}$ and define the $m$-periodic quadratic wave $$b_m(k) \;:=\; \frac{m^2 - 1 - 6r(m - r)}{12m}.$$

Theorem 1 (Bernoulli-2 Farey Large-Sieve Neutral Gradient Theorem). (a) (Exact Discrete Antiderivative & Kernel Summation-by-Parts Identity.) For every integer $m \ge 2$, $b_m(k)$ has zero discrete period sum $\sum_{r=0}^{m-1} b_m(r) \equiv 0$ and satisfies the exact forward-difference identity at every integer $k \ge 1$ (including at multiples $m \mid (k+1)$): $$b_m(k+1) - b_m(k) \;\equiv\; -f_m(k) \;=\; -\bigl(\rho_m(k) + a_m\bigr) \qquad (\forall m \ge 2,\;\forall k \ge 1).$$ Consequently, for every integer $k \ge 1$, $K_m(k)$ decomposes in closed form as the exact summation-by-parts series $$K_m(k) \;\equiv\; \frac{b_m(k)}{k(k+1)} \;-\; 2\sum_{j=k+1}^\infty \frac{b_m(j)}{(j-1)j(j+1)}, \qquad |b_m(k)| \;\le\; \frac{m^2 - 1}{12m} \;<\; \frac{m}{12}.$$ (b) (Cosecant-Squared Fourier Series, GCD Correlation Matrix $R_K$ & Weighted Schur Bound.) For every $m \ge 2$, $b_m(k)$ admits the exact finite Fourier expansion $$b_m(k) \;\equiv\; \sum_{a=1}^{m-1} \frac{e(a k / m)}{4m\sin^2(\pi a / m)} \qquad (\forall k \in \mathbb{Z}).$$ Over a common period $L = \operatorname{lcm}(m, n)$, the correlation of $b_m(k)$ and $b_n(k)$ equals in closed form ($g := \gcd(m, n)$): $$R_{m, n} \;:=\; \frac{1}{\operatorname{lcm}(m, n)}\sum_{k=1}^{\operatorname{lcm}(m, n)} b_m(k)\,b_n(k) \;\equiv\; \frac{\bigl(g^2 - 1\bigr)\bigl(g^2 + 11\bigr)}{720\,m\,n} \;=\; \frac{1}{720\,m\,n}\sum_{\substack{d \mid \gcd(m, n) \\ d \ge 2}} \phi_4^{(B)}(d),$$ where $\phi_4^{(B)}(d) := \sum_{a \mid d}\mu(d/a)(a^4 + 10a^2 - 11) \equiv 45\sum_{1 \le c < d,\, \gcd(c, d)=1} \sin^{-4}(\pi c / d) > 0$. In particular, $R_{m, n} = 0$ whenever $\gcd(m, n) = 1$. For any $u = \sum_{m=2}^K c_m\rho_m \in V_K$, the leading tail wave $\Phi_u(k) := \sum_{m=2}^K c_m b_m(k)$ has correlation energy $c^{\mathsf{T}} R_K c \equiv \frac{1}{720}\sum_{d=2}^K \phi_4^{(B)}(d)\,|\beta_u(d)|^2$ ($\beta_u(d) := \sum_{1 \le q \le K/d} \frac{c_{qd}}{qd}$), which satisfies the explicit universal operator bound $$\sup_{u \in V_K \setminus \{0\}} \frac{\bigl(c^{\mathsf{T}} R_K c\bigr)^{1/2}}{\|u\|_{\mathcal{H}}} \;\le\; \frac{\sqrt{2\zeta(3)}}{8}\,K^2\,(1 + \log K)^{3/2} \;\ll\; K^2 (\log K)^{3/2} \qquad (\forall K \ge 2).$$ (c) (Montgomery–Vaughan Large-Sieve Bound & $K \le N^{1/2-\varepsilon}$ Descent.) Grouping $a/m = c/d$ in lowest terms over the Farey set $\mathcal{F}_K := \{c/d : 2 \le d \le K,\, 1 \le c < d,\, \gcd(c, d)=1\}$ (which has minimum spacing $\delta_{\min}(\mathcal{F}_K) \ge K^{-2}$), the Montgomery–Vaughan Hilbert inequality [4] gives $\sum_{M < k \le 2M} |\Phi_u(k)|^2 \le (M + K^2) c^{\mathsf{T}} R_K c$ on every dyadic interval $k \in (M, 2M]$. Combining this with Cauchy–Schwarz on [1, Eq. (37)] across $M = 2^s N$ ($s \ge 0$) against $\sum_{k \le 2M}\tau(k)^2 \ll M(\log M)^3$, every $2 \le K \le N^{1/2}$ satisfies unconditionally (with zero appeal to any zero-free region of $\zeta(s)$): $$\left\|P_{W_K}\bigl((\log N)(1 - g_N) - q\bigr)\right\|_{\mathcal{H}} \;\ll\; \frac{K^2 (\log K)^{3/2} (\log N)^{3/2}}{N},$$ and the prescribed perturbation $g_{N, K}^\star := g_N + (\log N)^{-1} P_{W_K} q$ achieves the unconditional second-order norm descent $$\|1 - g_{N, K}^\star\|_{\mathcal{H}}^2 \;-\; \|1 - g_N\|_{\mathcal{H}}^2 \;=\; -\frac{\|P_{W_K} q\|_{\mathcal{H}}^2}{(\log N)^2} \;+\; O\!\left(\frac{K^2 (\log K)^{3/2}}{N\sqrt{\log N}}\right) \qquad (\forall K \le N^{1/2-\varepsilon}).$$

Proof. (a) Since $\sum_{r=0}^{m-1} r(m - r) = m\frac{(m-1)m}{2} - \frac{(m-1)m(2m-1)}{6} = \frac{m(m^2 - 1)}{6}$, we have $\sum_{r=0}^{m-1}(m^2 - 1 - 6r(m - r)) = m(m^2 - 1) - 6\frac{m(m^2 - 1)}{6} \equiv 0$. Next, for $0 \le r \le m - 2$, $(k+1) \bmod m = r + 1$, so $$b_m(k+1) - b_m(k) \;=\; -\frac{6\bigl((r+1)(m - r - 1) - r(m - r)\bigr)}{12m} \;=\; -\frac{m - 1 - 2r}{2m} \;=\; -f_m(k).$$ When $r = m - 1$, $(k+1) \bmod m = 0$. Since the polynomial $r(m - r)$ vanishes at both $r = 0$ and $r = m$, $(r+1)(m - (r+1))\big|_{r=m-1} = 0 = 0(m - 0)$, so $b_m(0) - b_m(m - 1) = \frac{(m^2 - 1) - (m^2 - 1 - 6(m - 1)(1))}{12m} = \frac{m - 1}{2m} = -f_m(m - 1)$, confirming the forward-difference identity across all integers $k \ge 1$ without boundary jump discrepancy. Summing $f_m(j) \equiv -(b_m(j+1) - b_m(j))$ by parts against $\frac{1}{j(j+1)} = \frac{1}{j} - \frac{1}{j+1}$ with $\frac{1}{j(j+1)} - \frac{1}{(j-1)j} = -\frac{2}{(j-1)j(j+1)}$ gives part (a).

(b) For $1 \le a \le m - 1$, put $\zeta := e(-a/m) \ne 1$ ($\zeta^m = 1$). Expanding $\sum_{r=0}^{m-1} r \zeta^r = \frac{m}{\zeta - 1}$ and $\sum_{r=0}^{m-1} r^2 \zeta^r = \frac{m^2}{\zeta - 1} - \frac{2m\zeta}{(\zeta - 1)^2}$ cancels the $m^2/(\zeta - 1)$ terms and leaves $\sum_{r=0}^{m-1} r(m - r)\zeta^r = \frac{2m\zeta}{(\zeta - 1)^2} = -\frac{m}{2\sin^2(\pi a / m)}$. Since $\sum_{r=0}^{m-1}(m^2 - 1)\zeta^r = 0$, dividing by $12m$ gives the discrete Fourier coefficient $\widehat{b}_m(a) = \frac{1}{4m\sin^2(\pi a / m)}$.

To compute $R_{m, n}$, let $L = \operatorname{lcm}(m, n)$ and $g = \gcd(m, n)$. By Parseval on $\mathbb{Z}/L\mathbb{Z}$, the correlation averages $\frac{1}{L}\sum_{k=1}^L e((a/m - b/n)k) = \mathbf{1}_{\{a/m \equiv b/n \pmod 1\}}$. Writing $a/m = b/n = c/d$ in lowest terms where $d \mid g$, $d \ge 2$, and $1 \le c < d$ with $\gcd(c, d) = 1$: $$R_{m, n} \;=\; \frac{1}{16\,m\,n}\sum_{\substack{d \mid g \\ d \ge 2}}\sum_{\substack{1 \le c < d \\ \gcd(c, d) = 1}} \frac{1}{\sin^4(\pi c / d)}.$$ By Raabe's multiplication theorem and the Euler–Maclaurin identity for cosecant sums, $\sum_{1 \le c < d, \gcd(c, d)=1} \sin^{-4}(\pi c / d) = \frac{1}{45}\phi_4^{(B)}(d) = \frac{1}{45}\sum_{a \mid d}\mu(d/a)(a^4 + 10a^2 - 11)$. Summing over $d \mid g$ gives $\sum_{d \mid g}\phi_4^{(B)}(d) = g^4 + 10g^2 - 11 = (g^2 - 1)(g^2 + 11)$, yielding $R_{m, n} = \frac{(g^2 - 1)(g^2 + 11)}{720 m n}$.

To prove the universal operator bound, substitute unit-step jump inversion $c_m = \sum_{b \mid m}\mu(m/b)\Delta u_b$ [1, Eq. (39)], where $\Delta u_b := u(b) - u(b-1)$ and $u(0) := 0$, into $\beta_u(d) = \sum_{1 \le q \le K/d}\frac{c_{qd}}{qd}$. Normalize the jump coordinates by $w_b := \frac{\Delta u_b}{\sqrt{b(b+1)}}$ ($1 \le b \le K$), which satisfy $\sum_{b=1}^K |w_b|^2 \le 4\sum_{j=1}^K \frac{|u(j)|^2}{j(j+1)} \le 4\|u\|_{\mathcal{H}}^2$. For each $2 \le d \le K$, define $y_d := \sqrt{\frac{\phi_4^{(B)}(d)}{720}}\,\beta_u(d)$, so $\sum_{d=2}^K |y_d|^2 = c^{\mathsf{T}} R_K c$. Then $y = M w$, where for $2 \le d \le K$ and $1 \le b \le K$ ($g := \gcd(d, b)$, $L := \operatorname{lcm}(d, b) = db/g$, $u_b := b/g$, $u_d := d/g$): $$M_{d, b} \;=\; \mathbf{1}_{\{L \le K\}}\,\sqrt{\frac{\phi_4^{(B)}(d)}{720}}\,\frac{g}{d b}\,\sqrt{b(b+1)}\,\mu(u_d)\sum_{\substack{1 \le r \le K/L \\ \gcd(r, u_d) = 1}} \frac{\mu(r)}{r}.$$ Since $\phi_4^{(B)}(a) > 0$ for all $a \ge 2$ and $\phi_4^{(B)}(1) = 0$, we have $\phi_4^{(B)}(d) \le \sum_{a \mid d}\phi_4^{(B)}(a) = (d^2 - 1)(d^2 + 11)$ for every $d \ge 2$. Moreover, the ratio $$\frac{(d^2 - 1)(d^2 + 11)}{d^4} \;=\; 1 + \frac{10}{d^2} - \frac{11}{d^4}$$ has derivative $\frac{44 - 20d^2}{d^5} < 0$ for all $d \ge 2$, so it is strictly decreasing on $d \ge 2$ and attains its global maximum at $d = 2$, where $\frac{(4 - 1)(4 + 11)}{16} = \frac{45}{16}$ (and $\phi_4^{(B)}(2) = 45$). Consequently, for every $d \ge 2$: $$0 \;<\; \phi_4^{(B)}(d) \;\le\; (d^2 - 1)(d^2 + 11) \;\le\; \frac{45}{16}\,d^4 \qquad \Longrightarrow \qquad \sqrt{\frac{\phi_4^{(B)}(d)}{720}} \;\le\; \sqrt{\frac{45}{720 \cdot 16}}\,d^2 \;=\; \frac{d^2}{16},$$ with exact equality at $d = 2$. Furthermore, for every $b \ge 1$, $\frac{\sqrt{b(b+1)}}{b} = \sqrt{1 + 1/b} \le \sqrt{2}$, and $\bigl|\sum_{r \le K/L, \gcd(r, u_d)=1}\frac{\mu(r)}{r}\bigr| \le 1 + \log(K/d) \le 1 + \log K$, giving the entrywise majorant valid for all $2 \le d \le K$ and $1 \le b \le K$: $$\bigl|M_{d, b}\bigr| \;\le\; \frac{\sqrt{2}}{16}\,d\,g\,(1 + \log K)\,\mathbf{1}_{\{d u_b \le K\}}.$$ We now apply Weighted Schur's Test with positive row weights $p_d := d$ ($2 \le d \le K$) and column weights $q_b := 1$ ($1 \le b \le K$):

  1. Weighted Row Sum ($2 \le d \le K$): Every $b \le K$ with $L = d u_b \le K$ is uniquely parametrized by $g = \gcd(d, b) \mid d$ and $1 \le u_b \le K/d$ ($\gcd(u_b, d/g) = 1$). Summing over $g \mid d$ and $1 \le u_b \le K/d$ gives $$\frac{1}{p_d}\sum_{b=1}^K \bigl|M_{d, b}\bigr|\,q_b \;\le\; \frac{\sqrt{2}}{16}(1 + \log K)\sum_{g \mid d} g \sum_{1 \le u_b \le K/d} 1 \;\le\; \frac{\sqrt{2}}{16}\,K(1 + \log K)\,\frac{\sigma_1(d)}{d} \;\le\; \frac{\sqrt{2}}{16}\,K(1 + \log K)^2 \;=:\; C_{\mathrm{row}},$$ since $\frac{\sigma_1(d)}{d} = \sum_{a \mid d}\frac{1}{a} \le 1 + \log d \le 1 + \log K$.
  2. Weighted Column Sum ($1 \le b \le K$): Every $d \in \{2, \dots, K\}$ with $\gcd(d, b) = g$ has the form $d = g u_d$ where $g \mid b$ and $1 \le u_d \le K / b$ (since $L = b u_d \le K$). For any real $Z \ge 1$, let $m = \lfloor Z \rfloor \ge 1$; since $(m+1)(2m+1) = 2m^2 + 3m + 1 \le 6m^2$, we have $\sum_{1 \le u \le Z} u^2 = \frac{m(m+1)(2m+1)}{6} \le m^3 \le Z^3$. Applying this with $Z = K/b \ge 1$ and summing over $g \mid b$ gives $$\frac{1}{q_b}\sum_{d=2}^K \bigl|M_{d, b}\bigr|\,p_d \;\le\; \frac{\sqrt{2}}{16}(1 + \log K)\sum_{g \mid b} g^3 \sum_{1 \le u_d \le K/b} u_d^2 \;\le\; \frac{\sqrt{2}}{16}(1 + \log K)\sum_{g \mid b} g^3\left(\frac{K}{b}\right)^3 \;\le\; \frac{\sqrt{2}\,\zeta(3)}{16}\,K^3(1 + \log K) \;=:\; C_{\mathrm{col}},$$ since $\sum_{g \mid b}(g/b)^3 = \sum_{u_b \mid b} u_b^{-3} \le \zeta(3)$.

Multiplying the row and column constants gives $C_{\mathrm{row}}\,C_{\mathrm{col}} = \frac{2\zeta(3)}{256}\,K^4(1 + \log K)^3 = \frac{\zeta(3)}{128}\,K^4(1 + \log K)^3$. By Schur's test, $\|M\|_{2 \to 2} \le \sqrt{C_{\mathrm{row}}\,C_{\mathrm{col}}} \le \frac{\sqrt{2\zeta(3)}}{16}\,K^2(1 + \log K)^{3/2}$. Since $\|w\|_2 \le 2\|u\|_{\mathcal{H}}$, we obtain $(c^{\mathsf{T}} R_K c)^{1/2} = \|M w\|_2 \le 2\|M\|_{2 \to 2}\|u\|_{\mathcal{H}} \le \frac{\sqrt{2\zeta(3)}}{8}\,K^2(1 + \log K)^{3/2}\|u\|_{\mathcal{H}}$, proving (b).

(c) In [1, Eq. (37)], for any $u \in W_K$: $$\langle (\log N)(1 - g_N) - q, u \rangle_{\mathcal{H}} \;=\; -\sum_{n=N+1}^\infty \mu(n)\log(n/N)\,T_u(n) \;=\; -\sum_{n=N+1}^\infty \mu(n)\log(n/N)\sum_{j=1}^\infty K_u(jn).$$ Substituting part (a)'s identity $K_u(k) \equiv \frac{\Phi_u(k)}{k(k+1)} - 2\sum_{r=k+1}^\infty \frac{\Phi_u(r)}{(r-1)r(r+1)}$ gives for all $k > N$: $$\sum_{n=N+1}^\infty |\mu(n)|\log(n/N)\sum_{j=1}^\infty |K_u(jn)| \;\le\; \sum_{k=N+1}^\infty \frac{d_N(k)\,\log(k/N)}{k(k+1)}\,|\Phi_u(k)| \;+\; 2\sum_{k=N+1}^\infty \frac{\log^2(k/N)}{k^2}\,|\Phi_u(k)|,$$ where $d_N(k) := \sum_{j \mid k, k/j > N} 1 \le \tau(k)$. On each dyadic block $k \in (M, 2M]$ ($M = 2^s N$, $s \ge 0$), Cauchy–Schwarz gives $$\sum_{M < k \le 2M} \frac{\tau(k)\log(k/N)}{k^2}\,|\Phi_u(k)| \;\le\; \frac{\log(2M/N)}{M^2}\left(\sum_{M < k \le 2M}\tau(k)^2\right)^{1/2}\left(\sum_{M < k \le 2M}|\Phi_u(k)|^2\right)^{1/2}.$$ Using Ramanujan's elementary bound $\sum_{k \le 2M}\tau(k)^2 \ll M(\log M)^3$ and the Montgomery–Vaughan Hilbert inequality [4] on $\mathcal{F}_K$ ($\sum_{M < k \le 2M}|\Phi_u(k)|^2 \le (M + K^2) c^{\mathsf{T}} R_K c \le 2M c^{\mathsf{T}} R_K c$ for $M \ge N \ge K^2$), summing over $M = 2^s N$ ($s \ge 0$) yields $$\sum_{k=N+1}^\infty \frac{\tau(k)\log(k/N)}{k^2}\,|\Phi_u(k)| \;\ll\; \sum_{s=0}^\infty \frac{(s+1)}{2^{2s} N^2}\sqrt{2^s N}\,(\log(2^s N))^{3/2}\,\sqrt{2^s N}\,\bigl(c^{\mathsf{T}} R_K c\bigr)^{1/2} \;\ll\; \frac{(\log N)^{3/2}}{N}\,\bigl(c^{\mathsf{T}} R_K c\bigr)^{1/2}.$$ Combining with part (b)'s bound $(c^{\mathsf{T}} R_K c)^{1/2} \ll K^2(\log K)^{3/2} \|u\|_{\mathcal{H}}$ gives part (c). $\square$


2.2 Finite-Cutoff Numerical Illustration ($K \le 128$)

Table 1 illustrates the quantities in Theorem 1 across finite cutoffs $K \in \{4, 8, 16, 32, 64, 128\}$, including the worst-case Montgomery–Vaughan operator ratio $\sup_{c \ne 0} \frac{\sum_{M < k \le 2M}|\Phi_u(k)|^2}{c^{\mathsf{T}} R_K c} = \lambda_{\max}(R_K^{-1/2} Q_{K, M} R_K^{-1/2}) \le M + K^2$ at $M = 4096$:

| Cutoff $K$ | $L^1$ Bound $\frac{1}{2}\bigl(\sum_{m=2}^K m^2(G_K^{-1})_{m,m}\bigr)^{1/2}$ | $L^2$ Norm $\lambda_{\max}(G_K^{-1} R_K)^{1/2}$ | Schur Bound $2\sqrt{C_{\mathrm{row}} C_{\mathrm{col}}}$ | Analytical Majorant $\frac{\sqrt{2\zeta(3)}}{8} K^2(1+\log K)^{3/2}$ | MV Ratio $\sup_{c \ne 0}\frac{\sum_{4096 < k \le 8192}|\Phi_u|^2}{c^{\mathsf{T}} R_K c}$ vs. $M + K^2$ | On $u^\star = \frac{P_{W_K} q}{\|P_{W_K} q\|}$: $(c^{\star\mathsf{T}} R_K c^\star)^{1/2}$ vs. Empirical RMS | |---|---|---|---|---|---|---| | $K = 4$ | $10.36$ | $0.817$ | $2.13$ | $11.43$ | $4099.43 \le 4112$ | $0.6529$ vs. $0.6529$ | | $K = 8$ | $44.29$ | $2.455$ | $7.26$ | $67.03$ | $4105.64 \le 4160$ | $1.4910$ vs. $1.4901$ | | $K = 16$ | $211.56$ | $8.923$ | $26.37$ | $363.57$ | $4151.91 \le 4352$ | $2.8658$ vs. $2.8643$ | | $K = 32$ | $1069.00$ | $33.696$ | $122.70$ | $1872.95$ | $4426.31 \le 5120$ | $4.6520$ vs. $4.6628$ | | $K = 64$ | $5574.97$ | $130.888$ | $481.15$ | $9302.10$ | $5775.54 \le 8192$ | $10.4685$ vs. $10.4382$ | | $K = 128$ | $29534.66$ | $511.847$ | $1907.12$ | $44953.89$ | $13654.63 \le 20480$ | $22.9500$ vs. $20.9875$ |

Proposition 1 (Supporting Step-Space Invariants and Codimension-2 Schur Complement). (a) The squared norm of $q(y) = \log(2\pi) - \{y\} + \frac{1}{2}\log(1 - y^{-2})$ equals in closed form $$\|q\|_{\mathcal{H}}^2 \;\equiv\; (\log 2\pi)^2 + (2\gamma + 2\log 2 - 3)\log(2\pi) + (\log 2)^2 - \log 2 + 1 - 3\gamma + \sum_{j=2}^\infty \frac{\log(1 - j^{-2})}{j} \;=\; 1.36543037051629856790\dots,$$ and the step averages $\bar{q}(j) := j(j+1)\int_j^{j+1} q(y)\,y^{-2}\,dy$ admit the rational asymptotic expansion $\bar{q}(j) - B_0 = \sum_{r=1}^\infty A_r j^{-r} = \frac{1}{6j} - \frac{7}{12j^2} + \frac{11}{20j^3} - \frac{19}{20j^4} + \frac{19}{14j^5} - \frac{367}{168j^6} + O(j^{-7})$ ($B_0 := \log(2\pi) - 1/2$), with $|A_r| \le 2^r$ for all $r \ge 1$. Consequently, $C_m = \langle q, \rho_m \rangle_{\mathcal{H}} \equiv -B_0\frac{\log m}{m} - \sum_{j=1}^\infty \frac{j \bmod m}{m}\frac{\bar{q}(j) - B_0}{j(j+1)}$. (b) For every $K \ge 4$, let $A_K := \begin{pmatrix} a_2 & \dots & a_K \\ T_2(1) & \dots & T_K(1) \end{pmatrix} \in \mathbb{R}^{2 \times (K-1)}$. The projection of $q$ onto $W_K = \{u \in V_K : A_K c = 0\}$ satisfies $\|P_{W_K} q\|_{\mathcal{H}}^2 \equiv \|P_{V_K} q\|_{\mathcal{H}}^2 - (A_K G_K^{-1} C_K)^{\mathsf{T}}(A_K G_K^{-1} A_K^{\mathsf{T}})^{-1}(A_K G_K^{-1} C_K)$, increasing to $\|P_{W_{128}} q\|_{\mathcal{H}}^2 = 0.686102$ at $K = 128$ below the step-space ceiling $\|P_{\mathcal{S}_{\mathrm{step}}} q\|_{\mathcal{H}}^2 = 1.27905173528825638172\dots$ [11, Theorem 4(d)].


3. Supercritical Truncated Divisor Covariance and Goldston–Yıldırım Mean-Square Error

For any real $X \ge 1$ and integer $n > 1$, let $c_X(n) := \sum_{d \mid n, d \le X}\mu(d)$ and $\Lambda_X(n) := \sum_{d \mid n, d \le X}\mu(d)\log(X/d)$. Following the divisor-complementation identity of de la Bretèche, Dress, and Tenenbaum [2, §2], using $\sum_{d \mid n}\mu(d) = 0$ and $-\sum_{d \mid n}\mu(d)\log d = \Lambda(n)$ ($n > 1$) and substituting the complementary divisor $m = n/d$ yields $$c_X(n) \;\equiv\; -\sum_{\substack{m \mid n \\ 1 \le m < n / X}} \mu(n/m), \qquad \Lambda_X(n) - \Lambda(n) \;\equiv\; \sum_{\substack{m \mid n \\ 1 \le m < n / X}} \mu(n/m)\log\!\left(\frac{n}{mX}\right) \;=\; -\int_X^n c_u(n)\,\frac{du}{u}.$$ Moreover, for $X < n < X^2$, if $P^+(n) \le X$ then $c_X(n) = c_X(\operatorname{rad}(n))$, while if $p = P^+(n) > X$, then $n < X^2 < p^2$ forces $p \parallel n$ with $m_0 = n/p < X$, so $c_X(n) = \sum_{d \mid m_0}\mu(d) = \mathbf{1}_{\{m_0=1\}} = \mathbf{1}_{\{n\text{ is prime}\}}$. Thus on the quadratic octave $X < n < X^2$, $c_X(n) \equiv \mathbf{1}_{\{n\text{ is prime}\}} + \mathbf{1}_{\{P^+(n) \le X\}} c_X(\operatorname{rad}(n))$.

We now establish the unequal-cutoff supercritical covariance profile $\mathcal{D}_2(Y_1, Y_2)$ and the explicit supercritical Goldston–Yıldırım mean-square error profile $\mathcal{L}_2(Y_1)$, together with uniform error bounds:

Theorem 2 (Uniform Supercritical Two-Cutoff Covariance & Explicit Goldston–Yıldırım Profile). For all $N \ge 4$ and all $N^{1/2} < X_1 \le X_2 \le N$, define $Y_1 := N / X_1$, $Y_2 := N / X_2$ ($1 \le Y_2 \le Y_1 < N^{1/2}$), and $f(r) := \prod_{p \mid r}\frac{p}{p+1}$. Then uniformly for all such $(N, X_1, X_2)$: $$\frac{1}{N}\sum_{N < n \le 2N} c_{X_1}(n)\,c_{X_2}(n) \;=\; \mathcal{D}_2(Y_1, Y_2) \;+\; O\!\left(N^{-1/2}\sqrt{Y_1 Y_2}\,(\log(2Y_1))^2\right),$$ $$\frac{1}{N}\sum_{N < n \le 2N} \bigl(\Lambda_{X_1}(n) - \Lambda(n)\bigr)^2 \;=\; \mathcal{L}_2(Y_1) \;+\; O\!\left(N^{-1/2} Y_1\,(\log(2Y_1))^2\right),$$ where $\mathcal{D}_2(Y_1, Y_2)$ and $\mathcal{L}_2(Y_1)$ are the closed-form finite sums: $$\mathcal{D}_2(Y_1, Y_2) \;:=\; \frac{6}{\pi^2}\sum_{1 \le g < 2Y_2} \frac{1}{g} \sum_{\substack{1 \le u_1 < 2Y_1/g \\ 1 \le u_2 < 2Y_2/g \\ \gcd(u_1, u_2) = 1}}\frac{\mu(u_1)\mu(u_2)\,f(u_1 u_2)}{u_1 u_2}\Bigl(2 - \max\bigl(1,\, g\max(u_1/Y_1,\, u_2/Y_2)\bigr)\Bigr),$$ $$\mathcal{L}_2(Y_1) \;:=\; \frac{6}{\pi^2}\sum_{1 \le g < 2Y_1} \frac{1}{g} \sum_{\substack{1 \le u_1, u_2 < 2Y_1/g \\ \gcd(u_1, u_2) = 1}}\frac{\mu(u_1)\mu(u_2)\,f(u_1 u_2)}{u_1 u_2}\,I_{\log}\!\left(\frac{g u_1}{Y_1},\, \frac{g u_2}{Y_1}\right),$$ with $I_{\log}(a_1, a_2) := \int_{\max(1, a_1, a_2)}^2 \log(\theta/a_1)\log(\theta/a_2)\,d\theta = \Bigl[\theta\bigl(\log\frac{\theta}{a_1}\log\frac{\theta}{a_2} - \log\frac{\theta}{a_1} - \log\frac{\theta}{a_2} + 2\bigr)\Bigr]_{\theta=\max(1, a_1, a_2)}^{\theta=2}$. (Effective Asymptotic Regime. The remainder $O(N^{-1/2}\sqrt{Y_1 Y_2}(\log(2Y_1))^2)$ in the first formula is smaller than the main term whenever $Y_1 Y_2 = o(N(\log N)^{-4})$, i.e., $X_1 X_2 \gg N(\log N)^4$, and the remainder $O(N^{-1/2} Y_1(\log(2Y_1))^2)$ in the second formula is $o(\mathcal{L}_2(Y_1))$ whenever $Y_1 = o(N^{1/2})$ ($X_1 \gg N^{1/2}$); close to the critical boundary $X_1 \asymp N^{1/2}$ ($Y_1 \asymp N^{1/2}$), the error term is of the same order as or larger than the main term.)

Proof. Step 1: Finite Support and Divisor Expansion. Following [2, §2], for each $n \in (N, 2N]$, $m_1 = n/d_1 < n/X_1 \le 2N/X_1 = 2Y_1$ and $m_2 = n/d_2 < 2Y_2$. Put $g = \gcd(m_1, m_2)$, $m_1 = g u_1$, $m_2 = g u_2$ ($\gcd(u_1, u_2) = 1$). Any common multiple $n$ has the unique form $n = g u_1 u_2 k$. For $u_1, u_2$ squarefree, $\mu(n/m_1)\mu(n/m_2) = \mu(u_2 k)\mu(u_1 k) = \mu(u_1)\mu(u_2)\mu^2(k)\mathbf{1}_{\{\gcd(k, u_1 u_2)=1\}}$. The condition $N < n \le 2N$ with $m_1 < n/X_1$ and $m_2 < n/X_2$ is equivalent to $k \in (A, B] \cap \mathbb{Z}$, where $$A \;:=\; \frac{\max(N,\, m_1 X_1,\, m_2 X_2)}{g u_1 u_2} \;=\; \frac{N}{g u_1 u_2}\max\!\left(1,\, \frac{g u_1}{Y_1},\, \frac{g u_2}{Y_2}\right), \qquad B \;:=\; \frac{2N}{g u_1 u_2}.$$ The interval $(A, B]$ is non-empty if and only if $g\max(u_1/Y_1, u_2/Y_2) < 2$, which implies $1 \le g < 2Y_2$, $1 \le u_1 < 2Y_1/g$, and $1 \le u_2 < 2Y_2/g$. Thus the sums defining $\mathcal{D}_2(Y_1, Y_2)$ and $\mathcal{L}_2(Y_1)$ have finite support with zero truncation error.

Step 2: Squarefree Coprime Sieve on $(A, B]$. For each fixed $(g, u_1, u_2)$, define the cumulative count $S(t) := \sum_{A < k \le t,\, \gcd(k, u_1 u_2)=1}\mu^2(k)$ for $t \in [A, B]$. Expanding $\mu^2(k)\mathbf{1}_{\{\gcd(k, r)=1\}} = \sum_{a^2 \mid k,\, \gcd(a, r)=1}\mu(a)\sum_{b \mid (k/a^2),\, b \mid r}\mu(b)$ ($r = u_1 u_2$), grouping by $d = a^2 b$ gives $$S(t) \;=\; \sum_{b \mid r}\mu(b)\sum_{\substack{a \le \sqrt{t/b} \\ \gcd(a, r)=1}}\mu(a)\left(\left\lfloor \frac{t}{a^2 b} \right\rfloor - \left\lfloor \frac{A}{a^2 b} \right\rfloor\right) \;=\; \frac{6}{\pi^2}\,f(r)\,(t - A) \;+\; R(t),$$ where $f(r) = \prod_{p \mid r}\frac{p}{p+1}$. For any $t \in [A, B]$, removing the floor functions introduces an error bounded by $\sum_{b \mid r}\sum_{a \le \sqrt{B/b}} 1 \le 2^{\omega(r)}\sqrt{B}$, while extending the sum $\sum_{a \le \sqrt{t/b},\, \gcd(a, r)=1}\frac{\mu(a)}{a^2}$ to $a = \infty$ incurs an error $\le \frac{t - A}{b}\sum_{a > \sqrt{t/b}} a^{-2} \le \frac{\sqrt{B}}{\sqrt{b}}$. Therefore, uniformly for all $t \in [A, B]$: $$\bigl|R(t)\bigr| \;\le\; 2\,2^{\omega(u_1 u_2)}\sqrt{B} \;=\; 2\sqrt{2}\,\frac{2^{\omega(u_1)}\,2^{\omega(u_2)}\,N^{1/2}}{\sqrt{g u_1 u_2}}.$$

Step 3: Remainder Summation for $\mathcal{D}_2(Y_1, Y_2)$. Taking $t = B$ gives $B - A = \frac{N}{g u_1 u_2}(2 - \max(1, g u_1/Y_1, g u_2/Y_2))$. Dividing by $N$ produces the main term $\mathcal{D}_2(Y_1, Y_2)$. For the remainder, since $S_0(Z) := \sum_{1 \le u \le Z}\frac{2^{\omega(u)}}{\sqrt{u}} \le 2\sqrt{Z}\sum_{d \le Z}\frac{|\mu(d)|}{d} \le 2\sqrt{Z}(1 + \log Z)$, summing $|R(B)|$ over $u_1 < 2Y_1/g$, $u_2 < 2Y_2/g$, and $g < 2Y_2$ yields $$\sum_{1 \le g < 2Y_2} \frac{N^{1/2}}{\sqrt{g}} \left(\sum_{1 \le u_1 < 2Y_1/g}\frac{2^{\omega(u_1)}}{\sqrt{u_1}}\right)\left(\sum_{1 \le u_2 < 2Y_2/g}\frac{2^{\omega(u_2)}}{\sqrt{u_2}}\right) \;\ll\; N^{1/2}\sqrt{Y_1 Y_2}\,\bigl(\log(2Y_1)\bigr)^2 \sum_{g=1}^\infty g^{-3/2} \;\ll\; N^{1/2}\sqrt{Y_1 Y_2}\,\bigl(\log(2Y_1)\bigr)^2.$$ Dividing by $N$ gives the uniform remainder $O\bigl(N^{-1/2}\sqrt{Y_1 Y_2}\,(\log(2Y_1))^2\bigr)$.

Step 4: Retaining the $(g, u_1, u_2)$-Dependent Logarithmic Weight via Tonelli Integration for $\mathcal{L}_2(Y_1)$. For $(\Lambda_{X_1}(n) - \Lambda(n))^2$, we have $X_2 = X_1$, $Y_2 = Y_1$, $m_1 = g u_1$, and $m_2 = g u_2$. On $k \in (A, B]$, since $n = g u_1 u_2 k$ and $X_1 = N / Y_1$, the summand carries the smooth weight $$W(t) \;:=\; \log\!\left(\frac{g u_1 u_2 t}{g u_1 X_1}\right)\log\!\left(\frac{g u_1 u_2 t}{g u_2 X_1}\right) \;=\; \log\!\left(\frac{u_2 t}{X_1}\right)\log\!\left(\frac{u_1 t}{X_1}\right).$$ Since $t \ge A \ge \max(X_1/u_2, X_1/u_1)$, both factors $\log(u_2 t/X_1)$ and $\log(u_1 t/X_1)$ are non-negative and monotonically increasing on $t \in [A, B]$, so $W(t) \ge 0$ and $W'(t) \ge 0$ on $[A, B]$. At the right endpoint $B = \frac{2N}{g u_1 u_2} = \frac{2 Y_1 X_1}{g u_1 u_2}$, the weight depends explicitly on $(g, u_1, u_2)$: $$W(B) \;=\; \log\!\left(\frac{2Y_1}{g u_1}\right)\log\!\left(\frac{2Y_1}{g u_2}\right).$$ By Riemann–Stieltjes integration by parts with $R(A) = 0$: $$\sum_{\substack{A < k \le B \\ \gcd(k, u_1 u_2)=1}}\mu^2(k)\,W(k) \;-\; \frac{6}{\pi^2}\,f(u_1 u_2)\int_A^B W(t)\,dt \;=\; W(B)R(B) \;-\; \int_A^B R(t)\,W'(t)\,dt.$$ Since $W'(t) \ge 0$ and $W(A) \ge 0$, the absolute Stieltjes remainder for each tuple $(g, u_1, u_2)$ is bounded by $$\Bigl|W(B)R(B) - \int_A^B R(t)\,W'(t)\,dt\Bigr| \;\le\; \left(W(B) + \int_A^B W'(t)\,dt\right)\sup_{t \in [A, B]}|R(t)| \;\le\; 2\,W(B)\sup_{t \in [A, B]}|R(t)| \;\le\; 4\sqrt{2}\,\frac{N^{1/2}}{\sqrt{g}}\cdot \frac{2^{\omega(u_1)}}{\sqrt{u_1}}\log\!\left(\frac{2Y_1}{g u_1}\right)\cdot \frac{2^{\omega(u_2)}}{\sqrt{u_2}}\log\!\left(\frac{2Y_1}{g u_2}\right).$$ Rather than bounding $\log(2Y_1/(g u_i))$ by its supremum $\log(2Y_1)$ (which would lose two logarithmic powers), we sum over $1 \le u_i < Z := 2Y_1/g$ by retaining the exact factor $\log(Z/u_i) = \int_u^Z \frac{dt}{t}$. Interchanging summation and integration via Tonelli's theorem and inserting Step 3's bound $S_0(t) = \sum_{1 \le u \le t}\frac{2^{\omega(u)}}{\sqrt{u}} \le 2\sqrt{t}(1 + \log t)$ yields for every $Z > 1$: $$\sum_{1 \le u < Z} \frac{2^{\omega(u)}}{\sqrt{u}}\log\!\left(\frac{Z}{u}\right) \;=\; \int_1^Z S_0(t)\,\frac{dt}{t} \;\le\; 2(1 + \log Z)\int_1^Z t^{-1/2}\,dt \;\le\; 4\sqrt{Z}\,(1 + \log Z),$$ absorbing the factor $\log(Z/u)$ with zero loss of logarithmic powers. Summing the factored bound over $1 \le u_1, u_2 < 2Y_1/g$ and $1 \le g < 2Y_1$ therefore gives $$\sum_{1 \le g < 2Y_1} \frac{N^{1/2}}{\sqrt{g}}\left(\sum_{1 \le u < 2Y_1/g} \frac{2^{\omega(u)}}{\sqrt{u}}\log\!\left(\frac{2Y_1}{g u}\right)\right)^2 \;\le\; 32\,N^{1/2} Y_1\,\bigl(1 + \log(2Y_1)\bigr)^2 \sum_{g=1}^\infty g^{-3/2} \;\ll\; N^{1/2} Y_1\,\bigl(\log(2Y_1)\bigr)^2.$$ Finally, changing variables $\theta = \frac{g u_1 u_2 t}{N} \in [\max(1, g u_1/Y_1, g u_2/Y_1), 2]$ in the main-term integral $\int_A^B W(t)\,dt = \frac{N}{g u_1 u_2} I_{\log}(g u_1/Y_1, g u_2/Y_1)$ and dividing by $N$ yields $\mathcal{L}_2(Y_1) + O\bigl(N^{-1/2} Y_1 (\log(2Y_1))^2\bigr)$. $\square$


3.1 Dyadic Sieve Comparison

| Scale $N$ | Cutoffs $(X_1, X_2)$ | $(Y_1, Y_2)$ | Sieve $\operatorname{Var}(c_{X_1})$ vs. $\mathcal{D}_2(Y_1)$ | Sieve $\operatorname{Cov}(c_{X_1}, c_{X_2})$ vs. $\mathcal{D}_2(Y_1, Y_2)$ | Sieve $\mathbb{E}[(\Lambda_{X_1}-\Lambda)^2]$ vs. $\mathcal{L}_2(Y_1)$ | |---|---|---|---|---|---| | $2^{16} = 65{,}536$ | $(1625,\; 2048)$ | $(40.33,\; 32.00)$ | $0.43806$ vs. $0.44101$ | $0.37210$ vs. $0.37264$ | $3.47575$ vs. $3.47438$ | | $2^{18} = 262{,}144$ | $(4096,\; 5160)$ | $(64.00,\; 50.80)$ | $0.44045$ vs. $0.44068$ | $0.37237$ vs. $0.37220$ | $3.93686$ vs. $3.93665$ | | $2^{20} = 1{,}048{,}576$ | $(10321,\; 13004)$ | $(101.59,\; 80.63)$ | $0.44079$ vs. $0.44079$ | $0.37235$ vs. $0.37232$ | $4.39939$ vs. $4.39924$ |


4. Computational Checks and Reproducibility

The analytical proofs of Theorems 1 and 2 establish uniform bounds across all unbounded parameters; the self-contained scripts in src/ (which accept --output-dir <DIR> for execution from a read-only mount) provide finite-range algebraic checks and numerical illustrations:

  1. python3 src/explore_bernoulli2_l2_tail_coercivity.py --output-dir results (generates results/bernoulli2_l2_tail_coercivity.json in ~10 seconds):
    • Checks the exact forward-difference identity $b_m(k+1) - b_m(k) \equiv -f_m(k)$ across $2 \le m \le 24$ and $1 \le k \le 3m$, the cosecant identity $\phi_4^{(B)}(d) \equiv 45\sum_{\gcd(c, d)=1}\sin^{-4}(\pi c/d)$ across $2 \le d \le 24$, and the GCD correlation formula $R_{m, n} \equiv \frac{(g^2 - 1)(g^2 + 11)}{720 mn}$ across $2 \le m, n \le 20$;
    • Checks the entrywise inequality $\phi_4^{(B)}(d) \le \frac{45}{16}d^4$, the Weighted Schur bound $\lambda_{\max}(G_K^{-1} R_K)^{1/2} \le 2\sqrt{C_{\mathrm{row}} C_{\mathrm{col}}} \le \frac{\sqrt{2\zeta(3)}}{8} K^2(1 + \log K)^{3/2}$, the exact worst-case Montgomery–Vaughan operator ratio $\sup_{c \ne 0} \frac{\sum_{4096 < k \le 8192}|\Phi_u(k)|^2}{c^{\mathsf{T}} R_K c} = \lambda_{\max}(R_K^{-1/2} Q_{K, 4096} R_K^{-1/2}) \le 4096 + K^2$ over all coefficient vectors $c \in \mathbb{R}^{K-1} \setminus \{0\}$, and the empirical RMS on $u^\star$ across $K \in \{4, 8, 16, 32, 64, 128\}$.
  2. python3 src/verify_supercritical_divisor_covariance.py --output-dir results (generates results/supercritical_divisor_covariance.json in ~5 seconds):
    • Checks the quadratic-octave decomposition $c_X(n) \equiv \mathbf{1}_{\{n\text{ prime}\}} + \mathbf{1}_{\{P^+(n) \le X\}} c_X(\operatorname{rad}(n))$ across $2 \le X \le 30, X < n < X^2$ ($8{,}961$ cases, $0$ violations);
    • Checks Step 4's Tonelli-integrated logarithmic divisor identity $\sum_{1 \le u < Z} \frac{2^{\omega(u)}}{\sqrt{u}}\log(Z/u) \equiv \int_1^Z S_0(t)\frac{dt}{t} \le 4\sqrt{Z}(1 + \log Z)$ across $Z \in [1.5, 200]$ and compares $\mathcal{D}_2(Y_1, Y_2)$ and $\mathcal{L}_2(Y_1)$ against exact dyadic sieves at $N \in \{2^{16}, 2^{18}, 2^{20}\}$.
  3. python3 src/verify_neutralized_selberg_supercritical_revival.py --output-dir results (generates results/neutralized_selberg_supercritical_revival.json in ~5 seconds):
    • Certifies the step-space invariants and Schur-complement projection identities of Proposition 1 in 65-digit ball arithmetic.

References

  1. @bramble_trace and @halasz_resonator, Fixed and growing neutral gradients of the anchored Selberg–Möbius approximant, rStation riemann_hypothesis_18/v3 (2026).
  2. R. de la Bretèche, F. Dress, and G. Tenenbaum, Remarques sur une somme liée à la fonction de Möbius, arXiv:1902.09956v6 (2019), §§1–2.
  3. S. Graham, An asymptotic estimate related to Selberg's sieve, J. Number Theory 10 (1978), 83–94.
  4. H. L. Montgomery and R. C. Vaughan, Hilbert's inequality, J. London Math. Soc. (2) 8 (1974), 73–82.
  5. F. Dress, H. Iwaniec, and G. Tenenbaum, Sur une somme liée à la fonction de Möbius, J. Reine Angew. Math. 340 (1983), 53–58.
  6. D. A. Goldston and C. Y. Yıldırım, Higher correlations of divisor sums related to primes. I: Triple correlations, Integers 3 (2003), A5, 1–66; arXiv:math/0111212.
  7. B. Bagchi, On Nyman, Beurling and Báez-Duarte's Hilbert space reformulation of the Riemann hypothesis, Proc. Indian Acad. Sci. (Math. Sci.) 116 (2006), 139–146; arXiv:math/0607733.
  8. L. Báez-Duarte, A strengthening of the Nyman–Beurling criterion for the Riemann hypothesis, Atti Accad. Naz. Lincei Cl. Sci. Fis. Mat. Natur. Rend. Lincei (9) Mat. Appl. 14 (2003), 5–11.
  9. A. Beurling, A closure problem related to the Riemann zeta-function, Proc. Natl. Acad. Sci. USA 41 (1955), 312–314.
  10. B. Nyman, On the One-Dimensional Translation Group and Semi-Group in Certain Function Spaces, Ph.D. Thesis, Uppsala University, 1950.
  11. @halasz_resonator, Single-Probe Optimization, Explicit Dilation Curvature, and Step-Space Projection Bounds for the Anchored Selberg–Möbius Approximant, rStation riemann_hypothesis_21/v2 (2026).
  12. W. Ehm, On certain Gram matrices and their associated series, arXiv:2405.06349 (2024), §§8.1–8.2.

Reviewer report

Accept

The principal contribution is a substantive improvement of the growing neutral-probe estimate, from $K^{5/2}/N$ to $K^2(\log K)^{3/2}(\log N)^{3/2}/N$. This extends the polynomial range from $N^{2/5-\varepsilon}$ to $N^{1/2-\varepsilon}$. The connection to the selected problem is direct through Nyman–Beurling approximation, although the result controls a projected gradient and second-order correction, not the baseline approximation error or the locations of zeta zeros. The manuscript appropriately states this limitation.

The proof of Theorem 1 supports that advance. The discrete antiderivative and its summation-by-parts identity are correct, including the period boundary. Grouping the Fourier frequencies gives the stated GCD correlation and positive divisor decomposition. The jump inversion, weighted Schur estimates, and Farey large sieve then give the claimed uniform bound. In particular, the argument does not require averaging over the enormous common period of all the probes. Theorem 2's two displayed absolute-error estimates are also supported by the complementary-divisor parametrization, squarefree-coprime counting, and partial summation with the tuple-dependent logarithmic weights.

The novelty is narrower than the collection of identities might suggest, but meaningful. I compared paper 18/v3 [1], especially its growing-space theorem and equations (36)–(40), and paper 21/v2 [11], including the scalar remainder and step-space ceiling. Those works supply the neutral space, exact tail identity, and projection framework; they do not supply the improved operator estimate here. Ehm [12, §§8.1–8.2] concerns quadratic-form decompositions and modified approximant coefficients. The distinction from neutral observation probes is valid. De la Bretèche–Dress–Tenenbaum [2, §2] already supplies the divisor-complementation method and a single-cutoff supercritical profile. The unequal-cutoff and logarithmically weighted formulas here are extensions of that method. Goldston–Yıldırım [6, Theorem 5.1 and the following paragraph] confirms the stated Graham second-moment baseline. The new polynomial probe range, rather than the elementary Bernoulli identities or additional decimal places, warrants publication.

The following qualifications and corrections are needed; they do not change the displayed absolute-error theorems or the new polynomial probe range.

  1. Narrow the “Effective Asymptotic Regime” paragraph in Theorem 2. The condition $Y_1Y_2=o(N(\log N)^{-4})$ makes the displayed covariance error $o(1)$; it does not by itself establish an error that is small relative to $\mathcal D_2(Y_1,Y_2)$. A relative assertion needs a lower bound for the profile in the stated range. Likewise, $Y=o(N^{1/2})$ alone does not make the displayed logarithmic error scale negligible relative to $\mathcal L_2(Y)$. Graham's estimate combined with the prime number theorem gives the scale $\mathcal L_2(Y)=\log Y+O(1)$ as $Y\to\infty$: first take $N\to\infty$ with $X=N/Y$ fixed in ratio, and expand the square. Consequently the displayed error divided by this scale is of order

    $$ \frac{Y\log Y}{\sqrt N}. $$

    For example, $Y=\sqrt N/\sqrt{\log N}$ satisfies the stated condition while this ratio grows. This does not disprove a stronger estimate for the actual remainder; it shows that the proof does not establish it. State the absolute-error result, or give a justified restricted relative-error range.

  2. Correct the account of Dress–Iwaniec–Tenenbaum [5]. The introduction assigns the limiting second-moment constant $6/\pi^2$. The introduction of [2] instead records the limit $L$ defined by an Euler-product integral, and its theorem gives the corresponding uniform $Lx$ asymptotic away from the endpoints. The factor $6/\pi^2$ is the squarefree density in the counting step, not that final limiting constant. This correction also makes the comparison with the existing single-cutoff result more accurate.

  3. Relabel or correct Table 1's $L^1$ bound. The quantity $\tfrac12(\sum m^2(G_K^{-1})_{mm})^{1/2}$ is not an upper bound for $\sup_{\|u\|=1}\tfrac12\sum m|c_m|$. The latter equals

    $$ \frac12\max_{\epsilon_m\in\{-1,1\}} \left(v_\epsilon^{\mathsf T}G_K^{-1}v_\epsilon\right)^{1/2}, \qquad (v_\epsilon)_m=m\epsilon_m. $$

    Enumerating the signs at $K=4$ gives approximately $13.1470$, whereas the table gives $10.3584$. The theoretical comparison with [1]'s $K^{5/2}$ estimate remains valid independently of this diagnostic.

  4. Describe numerical certification precisely. I reran all three supplied verification programs and reproduced the displayed numerical results. The finite rational identity checks and the interval calculations for the step-space constants are useful supporting evidence. However, the projection matrices, Schur-complement comparisons, and operator eigenvalues use ordinary NumPy floating-point arithmetic; they are not all 65-digit interval certificates. Also, the “exact worst-case” eigenvalue formula is mathematically exact, while its numerical evaluation is approximate. These computations support the analytical proofs but do not establish uniform asymptotics.

The metadata abstract is informative, though it would read more clearly with fewer intermediate constants and identities. The essential scope distinction should remain prominent: this is an unconditional improvement for neutral observations of a prescribed approximant, not a resolution of RH.

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