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The Numerical Framework — Interactive Paper

The Numerical Framework: A Damping Model, the Riemann Zeta Zeros, and the Proposed Integer Cutoff \(x_p=21\)
Eng. Abdulla M. N. Al-Jabri — Sana'a, Yemen | October 2026
v7.2 — 2026-10-26
Problem

How does the oscillatory structure interact with the damping factor in a function combining log, sine, and exponential, and what cumulative behavior results from this interaction?

Achievement

Definition of \(Z(x;21)=x^{-5}\ln x\sin(2\pi/x)e^{-x/21}\); analysis of its sign and roots (\(x=1\), \(x=2\)); study of its accumulation \(A(x)\) (which attains its global minimum at \(x=2\)). Derivation of the asymptotic envelope for the real function \(Z(x) \sim \frac{2\pi\ln x}{x^6}e^{-x/21}\), in addition to the asymptotic envelope of the complex extension \(K(x_p)\ln t/t^6\).

Type of Evidence

Analytic proof of the sign and roots of \(Z\); analytic proof of \(A_\infty<0\) via two standard inequalities (reviewed and confirmed); separate numerical verification (Appendix D) to check implementation and numerical consistency.

🔬 Interactive Simulation

Use the slider below to change the cutoff \(x_p\). The graph's range is extended to \(x=50\) to confirm that \(A(x; x_p)\) continues to increase and does not peak at \(x=42\).

21
* At \(x=2\): Minimum of \(A(x)\). * At \(x=42\): No peak, just continuous growth.
Note: The slider changes \(x_p\) for visual exploration only. The curve at \(x_p=21\) is the specific case used in the analytic proof in §3.

1. The Riemann Zero and Proposed Cutoff

Definition. Let \(\gamma_2 \approx 21.022039\) be the ordinate of the second positive nontrivial zero of the Riemann zeta function. We define the model parameter:

\[ x_p := \lfloor \gamma_2 \rfloor = 21. \]

Naming note. The choice \(x_p=21\) is a free modelling choice, inspired by \(\lfloor \gamma_2 \rfloor\) for numerical approximation purposes only. It is not a derivation from the zeta function, and the model makes no claim of a structural mathematical relationship between Riemann zeros and the function \(Z\).

The choice of 21 is a modelling choice inspired by a Riemann zero. It does not mean that \(\gamma_2 = 21.022\) is a root of \(Z(x)\) or \(Z'(x)\). On the study domain \(x \ge 1\), the roots of \(Z(x)\) are:
  • \(x=1\) at the boundary of the domain, since \(\ln 1 = 0\) and also \(\sin(2\pi)=0\).
  • \(x=2\), the unique interior root, since \(\sin(\pi)=0\).
Other zeros (e.g. \(x=2/3, 2/5\)) lie outside the simulation domain (\(x<1\)). The name "Yemeni Constant" is project-specific and does not connote established mathematical or physical significance.

2. Sign Analysis (Analytic Proof)

For \(x_p>0\), the real-variable function satisfies:

Click to view proof

For \(x>1\), the factors \(x^{-5}\), \(\ln(x)\), and \(e^{-x/x_p}\) are strictly positive. The sign is determined by \(\sin(2\pi/x)\). If \(1 < x < 2\), then \(\pi < 2\pi/x < 2\pi\), so the sine is negative. If \(x > 2\), then \(0 < 2\pi/x < \pi\), so the sine is positive. At \(x=1\), \(\ln x = 0\); at \(x=2\), \(\sin(2\pi/x)=0\). These are the only two roots in \([1,\infty)\).

3. Accumulation Function

Define \(A(x):=\int_1^x Z(t;21)\,dt\). By the Fundamental Theorem of Calculus, \(A'(x) = Z(x;21)\). Since \(Z(x)<0\) on \((1,2)\) and \(>0\) on \((2,\infty)\), \(A(x)\) decreases on \((1,2)\), attains a global minimum at \(x=2\), and increases on \((2,\infty)\).

Behaviour of \(A(x)\) at infinity

The integral \(A_\infty := \int_1^\infty Z(t;21)\,dt\) converges absolutely because of the factor \(e^{-t/21}\). Substituting \(t = 2\pi/x\):

\[ A_\infty = \frac{1}{(2\pi)^4} \int_0^{2\pi} W(t)\sin(t)\,dt, \qquad W(t) = t^3 \ln\!\left(\frac{2\pi}{t}\right) e^{-2\pi/(21t)}. \]

Splitting the integral over \((0,\pi)\) and \((\pi, 2\pi)\) and substituting \(t \mapsto 2\pi - t\) in the second part:

\[ \boxed{\,A_\infty = \frac{1}{(2\pi)^4} \int_0^\pi \bigl[W(t) - W(2\pi-t)\bigr]\sin(t)\,dt\,} \]
Click to view analytic proof that \(A_\infty < 0\)

Convention: In this proof, we use \(v\) (instead of \(A\)) for the auxiliary variable \(v = 2\pi/(\pi+u)\), to avoid confusion with the accumulation function \(A(x)\).

Step 1. Let \(\varphi(u) := \log W(\pi+u) - \log W(\pi-u)\) on \((0,\pi)\). We want to show \(\varphi(u) > 0\), i.e. \(W(2\pi-t) > W(t)\) with \(t=\pi-u\).

Step 2. \(\lim_{u\to 0^+}\varphi(u)=0\). It suffices to show \(\varphi'(u) > 0\). Differentiating \(\log W\):

\[ \varphi'(u) = \frac{g(v)}{\pi+u} + \frac{g(w)}{\pi-u} + \frac{2\pi}{21}\left(\frac{1}{(\pi-u)^2} + \frac{1}{(\pi+u)^2}\right), \]

where \(v = 2\pi/(\pi+u)\), \(w = 2\pi/(\pi-u)\), and \(g(s) = 3 - 1/\ln s\).

Step 3. Multiplying by \(2\pi\) and substituting (so that \(w = v/(v-1)\)):

\[ E(v) := 2\pi\varphi'(u) = \frac{3v^2}{v-1} - \frac{v}{\ln v} - \frac{v}{(v-1)\ln w} + \frac{v^2}{21}\!\left(1 + \frac{1}{(v-1)^2}\right). \]

For \(u\in(0,\pi)\), \(v = 2\pi/(\pi+u)\) lies strictly inside \((1,2)\).

Step 4 (positivity of \(E(v)\) on \((1,2)\)). Two standard inequalities:

  • For all \(v>1\): \(\ln v \ge \dfrac{2(v-1)}{v+1}\), strict for \(v>1\); hence \(-\dfrac{v}{\ln v} \ge -\dfrac{v(v+1)}{2(v-1)}\) (strict on \((1,2)\)).
  • On \((1,2)\): \(w = v/(v-1) > 2\), hence \(\ln w > \ln 2\), so \(-\dfrac{v}{(v-1)\ln w} > -\dfrac{v}{(v-1)\ln 2}\).

Substituting:

\[ \begin{aligned} E(v) &> \frac{v}{v-1}\left(\frac{5v-1}{2} - \frac{1}{\ln 2}\right) + \frac{v^2}{21}\!\left(1+\frac{1}{(v-1)^2}\right) \\ &> 0. \end{aligned} \]

On \((1,2)\), \(\dfrac{5v-1}{2} > 2\) (strict because \(v>1\); equality at \(v=1\) lies outside), and \(2 > \dfrac{1}{\ln 2}\approx 1.4427\), so the first bracket is positive. The second term is always positive. Hence \(E(v) > 0\) on all of \((1,2)\).

Step 5. Since \(v(u)\) remains inside \((1,2)\) on all of \((0,\pi)\), positivity of \(E(v)\) on \((1,2)\) gives \(\varphi'(u) > 0\). With \(\lim_{u\to 0^+}\varphi(u)=0\), we obtain \(\varphi(u) > 0\) for every \(u\in(0,\pi)\), i.e. \(W(2\pi-t) > W(t)\) on \((0,\pi)\).

Step 6. In the symmetric form:

\[ A_\infty = \frac{1}{(2\pi)^4}\int_0^\pi \bigl[W(t)-W(2\pi-t)\bigr]\sin t\,dt. \]

Since \(W(2\pi-t) > W(t)\) and \(\sin t > 0\), the integrand is negative pointwise, hence:

\[ \boxed{\,A_\infty = \frac{1}{(2\pi)^4}\int_0^\pi \bigl[W(t)-W(2\pi-t)\bigr]\sin t\,dt < 0\,} \]

Note. The above establishes \(A_\infty<0\) analytically and does not require numerical verification. The numerical verification in Appendix D is presented as a separate check of the implementation, not as a substitute for the proof.

Result. Since \(A(2)<0\), \(A'(x) = Z(x;21) > 0\) on \((2,\infty)\), and \(A_\infty < 0\):

Numerical integration note. The graph uses the trapezoidal rule with step \(h=0.05\) on \([1,50]\). The integral to infinity is estimated with an explicit tail bound using the damping factor \(e^{-x/21}\) (see Appendix D). The graph is exploratory; it does not replace the analytic proof above.

4. Complex Extension & Asymptotic Envelope

To examine behaviour along the critical line \(s=\tfrac12+it\), define an explicit complex extension using the principal branch of the logarithm \(\operatorname{Log}(s)\):

\[ \mathcal{Z}(s; x_p) = s^{-5} \operatorname{Log}(s) \sin\!\left(\frac{2\pi}{s}\right) e^{-s/x_p}. \]

As \(t \to \infty\), the asymptotic envelope for the complex extension is given by:

\[ |\mathcal{Z}(1/2+it; x_p)| \sim K(x_p)\frac{\ln t}{t^6}, \qquad K(x_p) = 2\pi e^{-1/(2x_p)}. \]
Important Note: Difference between the Real Function and Complex Extension (Audit v1.3):
The formula \(K(x_p)\ln t/t^6\) above applies only to the complex extension on the critical line \(s=1/2+it\), where the exponential factor \(e^{-s/x_p}\) becomes a constant in magnitude \(e^{-1/(2x_p)}\).

However, for the real function \(Z(x)\) as \(x \to \infty\), the exponential factor \(e^{-x/21}\) dominates and cannot be dropped. The correct asymptotic formula for the real function is: \[ Z(x) \sim \frac{2\pi\ln x}{x^6}e^{-x/21}, \qquad x\to\infty. \]
Scope. The asymptotic formula above is specific to the complex extension defined in this paper; it is not an asymptotic formula for the Riemann zeta function itself. The constant \(K(x_p)\) derives from this extension and is not asserted as a property of \(\zeta\).
Derivation and asymptotic equivalence

Principal branch. \(\operatorname{Log}(s) = \ln|s| + i\arg(s)\) with \(-\pi < \arg(s) \le \pi\).

Asymptotic equivalence. We write \(f(t) \sim g(t)\) iff \(\lim_{t\to\infty} f(t)/g(t) = 1\).

Derived result. The asymptotic envelope follows from the explicit complex extension, and describes the \(t\to\infty\) behaviour. It does not constitute a result about the Riemann zeta function itself.

5. Sensitivity Analysis & Evidential Status

Source of the target value. The value \(K \approx 6.1353\) is \(K(21) = 2\pi e^{-1/42}\) itself, computed from the model's own defining formula. Therefore the "agreement" between \(K(21)\) and \(6.1353\) is circular by construction, not an independent test.

The table below is best read as a sensitivity analysis of the choice of \(x_p\) over a bounded range (19–22), not as evidence that 21 is uniquely favoured. The comparison is informative about the curvature of \(K(x_p)\) around the chosen value, not about its uniqueness.

Candidate \(n\)\(K(n) = 2\pi e^{-1/(2n)}\)Diff \(|K(n)-6.1353|\)
196.1199950.015305
206.1280530.007247
216.1353530.000053
226.1419960.006696
Note on the nature of the comparison. The target value 6.1353 is \(K(21)\) itself. The positive entries in the third column for \(n \ne 21\) simply reflect the position of \(K(n)\) on the curve \(K(x_p) = 2\pi e^{-1/(2x_p)}\), which is slowly increasing. Minimality at \(n=21\) is by construction, not by independent discovery.

6. Methodological & Cosmological Extensions (Exploratory)

RiemannOS status. The wider cosmological interpretation (RiemannOS) and the proposed normalization \(Z+C+A=1\) are exploratory philosophical/physical hypotheses. This paper does not claim to prove the Riemann Hypothesis or derive cosmological constants.

A. Jabri-A hypothesis (dark energy)

In earlier drafts of the project, a numerically interesting coincidence was noted. If we define the roots \(t_k\) as those satisfying \(Z'(t_k) = 0\) (roots of the function \(Z\), not Riemann zeros), then evaluating the second derivative of the function \(Z\) — i.e. \(Z''(t_k)\), not a "second derivative of a physical potential" — at the fifth root \(t_5 \approx 32.935\) was reported to produce a very small numerical value of order \(10^{-123}\).

Terminological and numerical note. \(Z(x)\) is a purely mathematical model function, not a physical potential. The value \(Z''(t_5)\) has not been re-verified numerically in this version, and should be recomputed using the function \(Z\) defined in §1 before being treated as a numerical result. As for the comparison with the order of \(\Lambda \sim 10^{-122} M_{Pl}^2\), it is an exponential comparison only, not a physical comparison in unified units, until normalizations and units are specified.

Methodological note. This numerical observation does not constitute a basis for solving the cosmological constant problem, and is offered as an exploratory seed. Roots of \(Z'(t_k)=0\) are not zeros of the zeta function.

B. Jabri-C hypothesis (spacetime as execution of code)

A bolder philosophical hypothesis (Jabri-C) proposes that spacetime is not an independent stage but the "output" of a mathematical code. This is formalized hypothetically via an action linking Einstein's geometry to the field \(Z(x)\):

\[ S = \int d^4x \sqrt{-g} \left[ \frac{R}{16\pi G} + \frac{1}{2} \partial_\mu Z \partial^\mu Z - V(Z) \right] \]
Methodological note. This action is a philosophical simulation. No mathematical proof links Einstein's field equations to the roots of \(Z(x)\). These ideas are offered as seeds for thinking, not as established physical facts.

🛠️ 7. Computational Tools & Numerical Verification

To ensure reproducibility of the results and to verify the derivatives, the following tools are provided:

Z(x) Interactive Calculator (v5)
Computes the paper's model function \(Z(x)\) and its derivatives. Not the Riemann zeta function.
🧮 Open Calculator
Convergence Calculator (v5)
Partial sum \(Z_N(44)\) and its asymptotic behaviour. A standalone tool; results are not used to confirm this paper's conclusions unless the link is documented explicitly.
📈 Open Convergence Tool
Numerical Verification (Python — Appendix D)
Comparison of analytic and numerical evaluation of the complex extension, with an explicit tail bound.
📊 Verification Figure
Table status. The numerical values below come from Appendix D (§8). The "asymptotic expectation" column is \(K(21)\ln(t)/t^6\); the "numerical" column is the actual evaluation of the complex extension at \(s=1/2+it\).

Asymptotic formula: \(|\mathcal{Z}(1/2+it;21)| \sim K(21)\cdot\ln(t)/t^6\), where \(K(21) = 2\pi e^{-1/42} \approx 6.135353\).

Measured quantity: \(C(t) := |\mathcal{Z}(1/2+it;21)|\cdot t^6/\ln(t)\); expected \(C(t)\to K(21)\) as \(t\to\infty\).

Error definitions: "Absolute error" is \(|C(t)-K(21)|\); "relative error" is \(|C(t)-K(21)|/K(21)\).

\(t\) \(K(21)\cdot\ln(t)/t^6\)
(asymptotic)
\(|\mathcal{Z}(1/2+it;21)|\)
(numerical — §8)
\(C(t)\) \(|C(t)-K(21)|\)
(absolute)
\(|C(t)-K(21)|/K(21)\)
(relative)
\(10^2\) \(2.8254\times10^{-11}\) \(2.9860\times10^{-11}\) \(6.484090\) \(0.348738\) \(5.68\times10^{-2}\)
\(10^3\) \(4.2382\times10^{-17}\) \(4.3463\times10^{-17}\) \(6.291918\) \(0.156565\) \(2.55\times10^{-2}\)
\(10^4\) \(5.6509\times10^{-23}\) \(5.7325\times10^{-23}\) \(6.223935\) \(0.088583\) \(1.44\times10^{-2}\)
\(10^5\) \(7.0636\times10^{-29}\) \(7.1290\times10^{-29}\) \(6.192194\) \(0.056842\) \(9.26\times10^{-3}\)
\(t\to\infty\) \(0\) \(0\) \(K(21)=6.135353\) \(0\) \(0\)

Note on the final row: The 0 values in the "asymptotic expectation" and \(|Z|\) columns mean that as \(t \to \infty\), they approach zero, not that they have a finite value of zero.

Asymptotic Convergence. As \(t\to\infty\):

\[ C(t)=K(21)\left[1+\frac{\pi^2}{8(\ln t)^2} +O\!\left(\frac{1}{(\ln t)^4}\right)\right]. \]

Thus, the leading relative deviation from \(K(21)\) decays as \(1/(\ln t)^2\). This asymptotic expansion is derived analytically, explaining the slow convergence seen in the table.

Note on the expansion limits: The term \(\frac{\pi^2}{8(\ln t)^2}\) arises from the imaginary part of the complex logarithm. Contributions from other factors (such as \(s^{-5}\), \(\sin(2\pi/s)\), and the real part of the exponential) decay as powers of \(t\) (e.g., \(1/t, 1/t^2\)), which are much smaller than \((1/\ln t)^2\) as \(t\to\infty\).
Scope note. The formula \(|\mathcal{Z}(1/2+it;21)| \sim K(21)\ln(t)/t^6\) refers to the complex extension defined in this paper; it is not an asymptotic formula for the Riemann zeta function.

8. Appendix D — Numerical Verification Details

This appendix presents the details of the numerical verification (separate from the analytic proof) that supports the results, without replacing the proofs:

  1. Sign of \(A_\infty\): explicit tail bound plus a high-precision evaluation of \(A(100)\).
  2. Convergence of \(C(t)\): Python code to evaluate \(|\mathcal{Z}(1/2+it;21)|\) and compare with the asymptotic expectation (results in §7).

D.1 Tail bound for \(A_\infty\)

For all \(t \ge 2\), the bound \(|\sin(2\pi/t)| \le 2\pi/t\) holds. Since \(\ln t > 0\) on this domain,

\[ |Z(t;21)| = t^{-5}\ln(t)\,|\sin(2\pi/t)|\,e^{-t/21} \le 2\pi\, t^{-6}\ln(t)\,e^{-t/21}. \]

To bound the integral, note that \(g(t)=t^{-6}\ln t\) is decreasing for \(t\ge2\), since

\[ g'(t)=t^{-7}(1-6\ln t)<0. \]

Therefore, for every \(X\ge2\),

\[ \left|\int_X^\infty Z(t;21)\,dt\right| \le \int_X^\infty |Z(t;21)|\,dt \le 42\pi\, X^{-6}\ln X \cdot e^{-X/21}. \]

At \(X=100\):

\[ \left|\int_{100}^\infty Z(t;21)\,dt\right| \le 42\pi \cdot 100^{-6} \cdot \ln(100) \cdot e^{-100/21} \approx 5.2 \times 10^{-12}. \]

D.2 Code (Python — NumPy / SciPy)

import numpy as np
from scipy.integrate import quad

# D.1 — evaluate A(100) and the tail bound
def Z_real(t, xp=21.0):
    if t <= 1: return 0.0
    return (t**-5) * np.log(t) * np.sin(2*np.pi/t) * np.exp(-t/xp)

A_100, err_A100 = quad(Z_real, 1, 100, limit=500,
                       epsabs=1e-15, epsrel=1e-12)
X = 100.0
tail = 42*np.pi * X**-6 * np.log(X) * np.exp(-X/21.0)
print(f"A(100)      = {A_100:.12f}   (quad err: {err_A100:.1e})")
print(f"Tail bound  = {tail:.3e}")
print(f"A_inf < 0 (numerically supported): {A_100 + err_A100 + tail < 0}")
print()

# D.2 — evaluate |Z(1/2+it;21)|
def Z_cplx(s, xp=21.0):
    return (s**-5) * np.log(s) * np.sin(2*np.pi/s) * np.exp(-s/xp)

K21 = 2*np.pi*np.exp(-1/42)
print(f"K(21) = 2*pi*e^(-1/42) = {K21:.6f}")
print(f"{'t':>8} {'K ln(t)/t^6':>16} {'|Z|':>16} "
      f"{'C(t)':>10} {'|C-K|':>10} {'rel':>10}")
print("-" * 80)
for t in [1e2, 1e3, 1e4, 1e5]:
    z = abs(Z_cplx(0.5 + 1j*t))
    C = z * t**6 / np.log(t)
    err = abs(C - K21); rel = err / K21
    asymp = K21 * np.log(t) / t**6
    print(f"{t:>8.0e} {asymp:>16.4e} {z:>16.4e} "
          f"{C:>10.6f} {err:>10.6f} {rel:>10.2e}")

D.3 Result for \(A_\infty\)

Numerical evaluation and tail bound. The numerical integration gave \(A(100) \approx -0.0246463895708\), and scipy.integrate.quad reported an error estimate of approximately \(4.3 \times 10^{-16}\) in the reference execution. The analytic tail bound at \(X=100\) is less than \(5.2 \times 10^{-12}\).

The error estimate returned by quad is not a rigorous guaranteed bound; therefore, these results are presented as a strong numerical verification, not a formal computational certificate. Since the sign \(A_\infty < 0\) has already been proven analytically in §3, the final result does not rely on assuming the integration error estimate is a rigorous bound.

D.4 Reproducibility Notes

Limits of numerical verification. This verification is used to check the implementation of the formulas and numerical consistency with the asymptotic expectation. It does not constitute independent experimental evidence for a relationship between the model and the Riemann zeta function, and makes no claim about its zeros.
Changelog (v7.2 — 2026-10-26): Editorial fix in §3: the auxiliary variable in the proof of \(A_\infty < 0\) is now denoted \(v\) (instead of \(A\)), to avoid confusion with the accumulation function \(A(x)\). Notation-only change; no change to mathematical content or proof results.