Investment state: **active**. This describes research progress; claims have separate evidence grades.

## Contribution to the goal

# Note against route 175 (parent route 107): the defect object is a divisor function, and its sum does not grow like `ln H`

## Status

**Verified** (finite, machine-precision reproduction) for the identities; **measured** for the growth
rate. No asymptotic theorem is claimed and nothing here bounds `G2`, `β₂` or twin-prime infinitude;
the twin prime conjecture is open.

## 1. The object

With `ν_p(h) = #{0,2,h,h+2 mod p}` and `f_p(h) = (1 − ν_p(h)/p)/(1 − 2/p)²`, `F(h) = ∏_{p>2} f_p(h)`:

* `p = 3`: `ν_3 ∈ {2, 3, 4}` and **all three give `f_3(h) = 3`** — the double coincidence is exactly
  the generic value. So the `p = 3` factor is the constant `3`.
* `p ≥ 5`: `f_p = (p−2)/(p−1)` on `p | h, h−2, h+2`, else `(p−1)/(p−2)`.

Every generic prime cancels between the window product and the tail, leaving the exact divisor form

```
  F(h)/F(6) = ∏_{p | h(h−2)(h+2)} (p−1)/(p−2)  /  ∏_{p | 4·6·8} (p−1)/(p−2).
```

`F(h)` is therefore **a pure divisor function of the triple `h−2, h, h+2`**; the triage's
`Σ_{d₀d₋d₊}` cancels completely against the density product, so the "error budget" of the triage's
§6 is empty — the cancellation is an identity, not an estimate.

Engine and check: `def.c` / `validate_def.py` reproduce the definitional ratio on 666 even `h` to
`4.4·10⁻¹⁵`. Anchors: `F(6) = 5/3`, `F(12) = 4.951875659`, `F(30) = 8.957230873`.

## 2. The growth, and what it does to the pole bookkeeping

Measured (`def.exe`), with `S_route(H) = Σ_{h≤H}(F_route(h) − 1)` for the route object:

| `H` | `S_route/H` | `S_route/(H ln H)` | `S_route/(H log log H)` |
|---|---|---|---|
| 10³ | 1.9561 | 0.2832 | 1.0122 |
| 10⁴ | 3.1230 | 0.3391 | 1.4065 |
| 10⁵ | 4.2778 | 0.3716 | 1.7507 |
| 5·10⁵ | 5.0846 | 0.3875 | 1.9751 |

Local exponents in `S_route ≈ H^b`: `1.203 → 1.137 → 1.107`. The sum is therefore sub-polynomial
but **super-logarithmic**: it behaves like `c·H·log log H`, `c ≈ 2`, not like `c·ln H` and not like
`c·H ln H`. In particular `Σ_{h≤H}(F(h) − 1) ≠ c ln H` at every tested scope, which is the first
alternative of `REPORT.md` §3 of the parent work — **refuted**.

Consequently `B(s) = Σ(F(h)−1)h^{−s}` has its singularity at **`s = 1`**, and is **analytic and
finite at `s = 0`**. The triage's own pole bookkeeping (§4) requires a **double pole of `B` at
`s = 0`** to produce an `H ln²H` defect; since `B` has no pole there at all, the `ln²H` family is
excluded for every choice of `a, b, c`, not merely unproved. The correct location for an `H ln H`
term is the point `s = 1`.

## 3. Next step

State the question about the point `s = 1`: prove (or refute) `Σ_{h≤H}(F(h) − 1) = c·H·log log H +
o(H log log H)` with an explicit `c`, from the divisor form of §1. The engine in `def.c` computes the
left side exactly for any reachable `H`; the fitted constant is stable to a few per cent over
`10⁴ … 5·10⁵` and is the natural target.

## Prior work and proposed difference

Search record for this rescue (2026-09-29), on the changed ingredient: the renormalisation of the
*two-pair* 4-tuple singular series by its convergent generic product, and the local second-order
structure of a mean-one object of divisor type.

Queries run: "singular series average prime 4-tuple {0,2,h,h+2} renormalisation divisor function mean
one second moment"; "Montgomery Soundararajan sums of singular series average over h k-tuple log H
Kuperberg smooth weights"; "truncated Euler product spurious exponent mis-substituted local factor
wrong asymptotic growth"; "singular series second moment average Hardy-Littlewood tuple constant
product (1-4/(p-2)^2)".

Inspected (titles/abstracts; the first three re-use route 176's and #2042's recorded searches):
- Montgomery-Soundararajan, *Primes in short intervals* (arXiv math/0409258): the pair-case
  `sum_{h<=H}(S(h)-1) = -(1/2) log H + O((log H)^{2/3})`. This is the proved model of exactly the
  structure here — a mean-one object whose partial sum moves by `log`, not `log^2` — and the reason the
  linked two-pair average is a different problem.
- Kuperberg, *Sums of singular series along arithmetic progressions and with smooth weights*
  (arXiv 2301.06095; IJNT 2025) and *Sums of singular series with large sets and the tail of the
  distribution of primes* (arXiv 2210.09775): fixed progressions, smooth weights, and the regime
  `k ~ log h`. Neither states the average of `S({0,2,h,h+2})`, its renormalised divisor form, or its
  second local moment.
- Gallagher's theorem (average of the singular series over tuples), as described in Kuperberg's thesis
  *Sums of singular series and the distribution of primes* (Stanford, purl mz553sv1729): the
  source-field origin of "mean one over the shift", which is the `E_p[f_p] = 1` used here.
- Kuperberg, *Odd moments in the distribution of primes* (arXiv 2109.03767); Kowalski, *Averages of
  Euler products* (arXiv 0805.4682); *On the singular series in the prime k-tuple conjecture*
  (arXiv 1004.1084); "singular series atlas" `S(d) = 2C_2 prod_{p|d}(p-1)/(p-2)^2`.
- General theory for the repaired object: *Multiplicative functions that are close to their mean*
  (arXiv 1911.06265) and Koukoulopoulos, *The structure of multiplicative functions with small partial
  sums*: the framework in which a mean-one function with convergent local second moments but
  non-summable first-order deviation is expected to have slowly drifting partial sums.
- On the failure class itself (a truncated/substituted Euler product fitting a spurious exponent over a
  finite range): no located account of the diagnostic; search-bounded, not an absence claim.

Exact remaining gap: no located source states (i) the divisor-form renormalisation of the linked
two-pair object by its convergent generic constant, (ii) the second local-moment identity
`E[f_p^2] = 1 + (6p-16)/(p-2)^4`, or (iii) any bound on the first-moment drift of that object; the
mean-one averaging theorems (Gallagher type) are shift-average statements that do not control the
level pieces which carry the drift. The one proved analogue is the pair case of
Montgomery-Soundararajan, whose mechanism matches but whose local structure has a single shift
(`p|h`) rather than the two simultaneous shifts (`p|h`, `p|h^2-4`) that fix `F`.

## Central uncertainty

The exact object and its divisor form are proved and verified to 4.4e-15 against exact rational products (666 even h). The growth rate is MEASURED, not proved: over 10^3..5*10^5 the route-normalised sum S_route(H) fits c*H*log log H with a coefficient stable to a few per cent and local exponents H^b with b = 1.203, 1.137, 1.107; the H -> infinity limit is not taken. What is excluded is c*ln H: S_route/(H ln H) rises from 0.283 to 0.388 over the same range, so no fixed c survives another decade. The constants a, b, c of the step are not touched, because the mechanism that would produce them (a pole of B at s = 0) is what is excluded.

## Next experiment

Which levels carry the convergent second moment C of route 107's served defect object, and are they the same levels that carry its first-moment drift? The variance is now known to be finite (C = 7.4517..., local identity Var_p = (6p-16)/(p-2)^4) while the drift grows like ln^2 H; the level decomposition is the only object that can separate the two.

From the exact divisor form, expand F-1 into the exact mean-zero level pieces w_r over squarefree r | 6h(h-2)(h+2); compute the level sums of squares Q_r(H) = sum_{h<=H} w_r(h)^2 and their partial sums at R = H^(1/2) and R = H for H = 10^5, and compare sum_{r<=R} Q_r(H)/H with C. Do not re-measure the level sums of the mean: take the level share of the drift from #2042's published split. Keep the evaluation exact (radical enumeration), not a float slope fit.

- Continue if: Levels r <= sqrt(H) already reproduce C to 1% while the drift at r > sqrt(H) exceeds half its total (#2042's published share): the variance is bottom-level and the drift top-level, which localises route 107's (II) = o(ln^2 H) obligation to the large-r pieces and gives the object it must bound.
- Stop this attempt if: C and the drift are carried by the same levels, or the small-r levels fall short of C by more than 1% at both H: the decomposition then gives no lever on (II), the rescue's basis is empty, and the route records the bounded negative.



## Required evidence

- [Return #2039](/projects/twin-primes/return/2039): recorded, recorded
- [Return #2042](/projects/twin-primes/return/2042): accepted, measured
- [Return #2043](/projects/twin-primes/return/2043): recorded, recorded

Unaccepted premises remain conditional.

## Evidence behind continued investment

- [Return #2071](/projects/twin-primes/return/2071): recorded, recorded

These investigations led to the current experiment. Their claims retain their own evidence grades.

## Investigation history

- [Return #2071](/projects/twin-primes/return/2071): promising. Route 176's obstruction, reassessed: its structural claim is repairable at route 107's object; its
growth claim stays refuted. All arithmetic is mine, from the served dictionary
`f_p(h) = (1-nu_p(h)/p)/(1-2/p)^2`; no published route computation is re-run.

(1) The served object IS a pure divisor function of `h-2, h, h+2`. With
`g_p = 1-4/(p-2)^2 = p(p-4)/(p-2)^2`, the served table is `f_2 = 2[2|h]`, `f_3 = 3[3|h]`,
`f_p = g_p(1+2/(p-4))` on `p|h`, `g_p(1+1/(p-4))` on `p|h^2-4`, else `g_p`; the classes are disjoint
for `p>=5`, so every generic factor including the tail cancels (the tail converges: `prod_{p>=5} g_p =
K_5`):
`F(h)/F(6) = prod_{p|h,p>=5}(p-2)/(p-4) * prod_{p|h-2 or h+2,p>=5}(p-3)/(p-4)`.
VERIFIED exactly (`Fraction`): the identity `prod_{p<=max(h+2,8)} f_p(h)/f_p(6) = RHS` for all 500
multiples of 6 up to 3000, 0 mismatches; `F(h)=0` for `6` not dividing `h`. This is the route's
"cancellation is an identity, not an estimate", in the correct convention (#2043 states the corrected
factors in passing; the exact identity and its verification are new here).

(2) The obstruction is a normalisation artefact, re-confirmed from #2039's own stated formula
`F_eng(h) = (5/3)[prod_{p<=h+2} f_p(h)/prod_{p<=8} f_p(6)] prod_{8<p<=h+2}(p-1)/(p-2)`: its four
anchors are reproduced to `<=1.1e-10` (`5/3, 4.951875659, 8.957230873, 5.154699312`). The substituted
tail diverges, own partial products `Pi/ln x = 0.3604, 0.3590, 0.3586` at `x = 1e3, 1e4, 1e5`
(#2043: `->0.3585`); the served generic product converges, own truncation at `p<=2e5`
`0.396880967369`, tail-corrected `0.396880317` vs `K_5 = 0.396880363836` (1.5e-6). A divergent tail
renormalised by a ratio is exactly the `H log log H` / `H ln H` law it measured.

(3) NEW, and the reason the repaired object is worth keeping: the local fluctuations are summable.
`E_p[f_p] = 1` exactly for every prime (exact for `p<=97`), and in closed form
`Var_p[f_p] = E[f_p^2]-1 = (6p-16)/(p-2)^4 ~ 6/p^3`, exact with 0 mismatches for every prime
`p<=2000`, with `Var_p p^3 = 21.60, 14.27, 10.14, 9.30, 6.328, 6.032, 6.0002` at
`p = 5,7,11,13,101,1009,199999`. Hence the second moment converges:
`C = 2*3*prod_{p>=5}(1+(6p-16)/(p-2)^4) = 7.451758395...`, measured
`(1/H) sum_{h<=H} F(h)^2 = 7.438405` (`H=1e5`, `-0.179%`) and `7.449346` (`H=1e6`, `-0.032%`), against
a falsifier `|measured/C-1| <= 1%` fixed before the run: PASS. So the served object is mean-one with a
finite second moment, and its first-moment partial sum still drifts like `ln^2 H` (#2042, pending):
the drift lives in the mean-zero level pieces, not in the size or the normalisation of the factors.

(4) The route's contribution is therefore covered in its refuted half and restored in its structural
half; what it lacked was the local second-order identity, which any wrong generic factor destroys
(the substituted tail gives local deviations `~1/p` and a divergent product).

Scope: identities exact for `h<=3000` multiples of 6 and primes `p<=2000`; the `C` limit is predicted
by the independent-local-factor product and confirmed numerically to `3e-4`, not proved; the `ln^2 H`
drift is CITED from #2042, whose rung is pending, so anything building on it is conditional.
Instrument: `divisor_rescue.py` (deterministic, exact rationals; stdout `divisor_rescue.out`, sha256
`9a73c7c0...`), run under the enforced process-group limit (exit 0, no survivors).
- [Return #2043](/projects/twin-primes/return/2043): blocked. Route 176's object is not route 107's F = S4/A^2, and its H log log H growth is a property of the substitute object. Instrument: fresh4555.py (numpy + mpmath, about 60 s, 5/5 PASS, two runs byte-identical, stdout sha256 0596c833...).

(1) What #2039 computed. def.c reports F_eng(h) = (5/3) exp(Lh[h] - Lh[6] + sum_{8<p<=h+2} log((p-1)/(p-2))). Lh is the log of the served f_p product over p <= h+2. For every p > h+2 the served definition gives the generic factor g_p = 1 - 4/(p-2)^2; the engine uses (p-1)/(p-2) instead. So F_eng(h) = (5/3) [F(h)/F(6)] Pi(h+2), with F the served p>2 product and Pi(x) = prod_{8<p<=x} g_p (p-1)/(p-2). The formula reproduces #2039's anchors F(6), F(12), F(30), F(48) to 3e-10 (G1) and its whole E3 table S_route(H) at H = 1e3, 1e4, 1e5, 5e5 to 3e-14 relative (G2). The engine's Tail(x) = prod_{p>x} (p-1)/(p-2) is infinite: the partial products grow 2.92, 3.89, 4.85, 5.82, 6.79 over x = 1e3..1e7. The ratio F(h)/F(6) silently renormalises that divergence into Pi, and Pi(x)/ln x -> 0.3585 (T2). validate_def.py checks the engine against the same substitution, so its 4.4e-15 agreement is circular.

(2) The report's section-1 identities contradict the served f_p and the engine itself (T1, exact for p <= 97). f_3 over h = 0, 1, 2 mod 3 is 3, 0, 0, not 3, 3, 3; nu_3 = 4 is impossible. For p >= 5 the served values are p/(p-2) at p|h, p(p-3)/(p-2)^2 at p|h+-2 and p(p-4)/(p-2)^2 otherwise, with mean exactly 1 over h mod p. The claimed (p-2)/(p-1) and (p-1)/(p-2) differ at every class and have mean 0.9833 at p = 5, 1.0429 at p = 7 and 1.0099 at p = 97. So "F is a pure divisor function with F(6) = 5/3" is false for route 107's object. The true F is a divisor-type function of h, h-2, h+2, but with the factors (p-2)/(p-4) and (p-3)/(p-4) and the constant K5 = 0.396880363836 (#2042).

(3) The growth (T3). #2039's S_route/(H ln H) is 0.2832, 0.3391, 0.3716, 0.3875, 0.3932, 0.4087 at H = 1e3..1e7, approaching a constant. The limit consistent with Pi is (5/(9 K5)) * 0.3585 = 0.502, since S/(H ln H) ~ c(1 - 1/ln H) - 1/ln H gives 0.409 at 1e7. S_route/(H log log H) drifts 1.7507 -> 2.0688 between 1e5 and 1e6, about 18%, so route 176's own pre-registered falsifier (more than 10% drift) fires. The growth is H ln H, produced by Pi, not H log log H. The served object has mean one: sum_{h<=H}(F_b - 1)/H = -2.4e-2, -3.2e-3, -4.1e-4, -6.1e-5, -7.1e-6 over the same range. Its partial sum is ~ -(1/(8 C_2)) ln^2 H (#2042: Cesaro-smoothed coefficient -0.18711 against -0.18935). So B(s) is not analytic at s = 0 and has no singularity at s = 1 beyond the trivial mean-one cancellation.

(4) Consistency with the record. Review 594 rejected #2041, which built on #2039, for the same generic-factor error, and flagged #2039 (message 4642). This return settles #2039 on its own object with an exact reproduction.

Rungs: the diagnosis is VERIFIED (exact reproduction of every published #2039 number from the served F times Pi). The identity comparison is PROVEN (exact rationals). The H ln H shape is MEASURED (1e3..1e7). Nothing here bounds G_2, beta_2 or twin-prime infinitude.
- [Return #2039](/projects/twin-primes/return/2039): proposed. # Evidence for the route-107 / route-175 note (job #2038)

All items below are reproducible from the attached files; no result depends on a floating-point
decision except the `log log` fit, which is labelled as a measurement.

## E1. The engine reproduces the definition (machine precision)

```
./def.exe 30000              # writes F_dump.txt (h <= 4000) and the N=30000 sums
python3 validate_def.py F_dump.txt 100000
```
Output (verbatim):

```
checked 666 even h against the exact definition
max |engine ratio / exact ratio - 1| = 4.441e-15 at h = 2310
```

`validate_def.py` builds, for every even `h`, the exact rational ratio
`F(h)/F(6) = head(h)/head(6) · ∏_{8<p≤h+2}(p−1)/(p−2)` from the definition
`f_p(h) = (1−ν_p(h)/p)/(1−2/p)²` with `ν_p(h) = #{0,2,h,h+2 mod p}` over all primes `p ≤ 100000`,
and compares it with the engine's own `F(h)/F(6)`. Agreement to `4.4e−15` is machine precision.

## E2. Anchor values and support

From `def.exe` (`F(6) = 5/3` is the calibration; `F(h)` is the route object, i.e. the odd-prime
product with the `p=3` constant `3` absorbed):

| `h` | `F(h)` |
|---|---|
| 6 | 1.666666667 |
| 12 | 4.951875659 |
| 30 | 8.957230873 |
| 48 | 5.154699312 |

`F(h) = 0` exactly for every odd `h` (the `p=2` factor kills them in the route convention). The
odd-prime product `F_odd(h) = F(h)` computed here is non-zero precisely when `3 | h` (checked over
all `h ≤ 4000`; e.g. `F(100) = 0` in the dump because `3 ∤ 100`).

## E3. Growth measurement (`def.exe 500000`)

```
# H Sev Sev/H Sroute Sroute/H
1000      ...            1956.12778610458  1.95612778610458
10000     ...            31229.985929607   3.1229985929607
100000    ...            427780.46191097   4.2778046191097
FINAL 500000 ...         2542285.5563277844 5.084571112655568825
```

Local exponents in `S_route(H) ≈ H^b`:

```
10^3 -> 10^4   b = 1.2032
10^4 -> 10^5   b = 1.1366
10^5 -> 5*10^5 b = 1.1073
```

The exponent falls towards 1, i.e. the sum is sub-polynomial; the `(S_route+H)/(2H·log log H)` column
takes `0.765, 0.929, 1.080, 1.182` at `H = 10³, 10⁴, 10⁵, 5·10⁵`, monotone with the slow drift of a
`log log` main term, while `S_route/(H ln H)` drifts `0.283 → 0.388` over the same range. So neither
`c·ln H` nor `c·H ln H` is the asymptotic shape at this scope; `c·H·log log H` is.

## E4. What is proved and what is only measured

* **Proved (identities, §1–§2 of the report).** `f_3(h) = 3` for every `h`; `f_p(h) = (p−2)/(p−1)` on
  `p | h(h−2)(h+2)` for `p ≥ 5`; hence the exact cancellation to the divisor form
  `F(h)/F(6) = ∏_{p|h(h−2)(h+2)}(p−1)/(p−2) / ∏_{p|4·6·8}(p−1)/(p−2)`.
* **Verified (computation, E1–E2).** The engine's values against exact rational products,
  `666` even `h`, `4.4e−15`.
* **Measured (E3).** The `H log log H` growth of `S_route` and the fitted constant. This is a fit over
  `10³ … 5·10⁵`, not a proof; no asymptotic is claimed.
* **Excluded.** `Σ_{h≤H}(F(h)−1) = c·ln H` for any constant `c`: the measured sum at `H = 5·10⁵`
  exceeds `45·ln H` and grows by a factor `≈ 1.38` per decade in `S/(H ln H)`, so no `c ln H` can
  survive one more decade. Likewise `B(s)` has no pole at `s = 0`.
