> Full-text translation from Chinese. The original remains authoritative for its research claims; this translation is not independent mathematical verification.

# DMSD Phase 3C — Cross-Base Prime Projection Audit

**Date:** 2026-09-30  
**Status:** COMPLETE  
**Exact prime bound:** \(10^7\)  
**Scale grammars:** base 2 / 8 / 10 / 16

---

## 1. Question

In Phase 3B, the decimal scale:

\[
L_k^{(10)}=[10^k,10^{k+1})
\]

revealed several attractive finite patterns:

- normalized center bias is negative;
- bias magnitude decreases with scale;
- adjacent-scale normalized histograms become increasingly similar;
- prime density decreases with scale.

But DMSD itself already requires:

\[
\boxed{
\text{Representation Artifact Audit}
}
\]

We therefore cannot take an attractive decimal plot directly as prime ontology.

This round reprojects the same exact prime data onto scales with:

\[
b\in\{2,8,10,16\}
\]

namely:

\[
L_k^{(b)}=[b^k,b^{k+1}).
\]

---

# 2. Primes remain unchanged; the scale grammar changes

For any prime \(p\), its primality does not change with the base.

But:

\[
k_b(p)=\lfloor \log_b p\rfloor
\]

and:

\[
\lambda_{b,k}(p)
=
\frac{p-b^k}{b^{k+1}-b^k}
\]

both depend on the base.

Therefore:

\[
\boxed{
\text{Prime Ontology}
\neq
\text{Scale Projection Geometry}.
}
\]

This round audits the latter.

---

# 3. Exact scales

Using shared exact prime data with:

\[
p<10^7
\]

the numbers of complete scales are:

```text
base 2:  23 scales
base 8:   7 scales
base 10:  7 scales
base 16:  5 scales
```

Different bases have different scale widths, so the scale counts should not be equal in the first place.

---

# 4. Refinement correctness

For every complete scale block, we compute normalized histograms with:

\[
R=10,100,1000
\]

these resolutions.

Then we check:

\[
100\to10,
\qquad
1000\to100,
\qquad
1000\to10.
\]

The refinement relations for every base / scale all:

```text
PASS
```

Changing the base therefore does not break DMSD's:

\[
\boxed{
\text{Fine Histogram}
\rightarrow
\text{Coarse Histogram}
}
\]

exact partition certificate.

---

# 5. Cross-base partition sanity

We randomly sample:

```text
500
```

exact primes.

For each base \(b\), we independently determine:

\[
k_b
\]

and check:

\[
b^{k_b}\le p<b^{k_b+1}.
\]

Result:

```text
500 / 500 PASS
```

All four scale grammars are therefore valid partitions of the same prime domain.

---

# 6. Center Bias: the sign survives across bases for now; the magnitude does not

For each scale, define:

\[
B_{b,k}
=
\operatorname{mean}(\lambda_{b,k}(p))
-\frac12.
\]

The last four complete scales for each base:

### base 2

\[
-0.004168,\;
-0.004023,\;
-0.003754,\;
-0.003648
\]

### base 8

\[
-0.016983,\;
-0.015982,\;
-0.013392,\;
-0.011134
\]

### base 10

\[
-0.018351,\;
-0.015020,\;
-0.012937,\;
-0.010933
\]

### base 16

\[
-0.042361,\;
-0.023361,\;
-0.018819,\;
-0.014666
\]

Within the current finite exact range, the high-scale tails for all four bases have:

\[
\boxed{
B_{b,k}<0.
}
\]

But the magnitude is highly base-dependent.

A more reasonable current classification is therefore:

\[
\boxed{
\text{negative-bias sign: finite cross-base persistent observation}
}
\]

whereas:

\[
\boxed{
\text{bias magnitude: representation-sensitive}.
}
\]

Decimal values such as \(-0.0109\) cannot be called prime invariants.

---

# 7. Why is the bias smaller in base 2?

There is a very natural explanation here.

A base 2 scale:

\[
[2^k,2^{k+1})
\]

spans only a factor of 2.

A base 10 scale:

\[
[10^k,10^{k+1})
\]

spans a factor of 10.

Base 16 spans an even larger factor of 16.

If prime density decreases slowly with \(x\), then the wider a multiplicative interval is:

> the more pronounced the difference in average density between its left and right ends.

The base dependence of normalized center bias is therefore not mysterious,
and is compatible with a prime-number-theorem-type density-decay picture.

This is only a structural explanation, not a claim of a new theorem.

---

# 8. Adjacent-scale histogram similarity

For each base, we compute adjacent-scale JS divergence for 100-bin normalized histograms.

High-scale tails:

### base 2

\[
2.22\times10^{-4},
\;
1.04\times10^{-4},
\;
4.88\times10^{-5}
\]

### base 8

\[
1.91\times10^{-2},
\;
1.91\times10^{-3},
\;
1.88\times10^{-4}
\]

### base 10

\[
4.68\times10^{-3},
\;
4.95\times10^{-4},
\;
5.75\times10^{-5}
\]

### base 16

\[
3.25\times10^{-1},
\;
1.27\times10^{-2},
\;
6.16\times10^{-4}
\]

All four bases show a decrease at the tail of the current finite scales.

This is more interesting than a decimal-only observation, because:

\[
\boxed{
\text{adjacent-shape similarity increase}
}
\]

does not immediately disappear after changing the base.

But it can still only be called:

\[
\boxed{
\text{cross-base persistent finite pattern}.
}
\]

not a convergence theorem.

---

# 9. Nearest-Magnitude Audit

To avoid directly comparing entirely different magnitudes,
this round uses the log-magnitude midpoints of the decimal scales:

\[
L_2,\ldots,L_6
\]

as anchors.

For each other base, we choose the scale with the nearest midpoint.

The results show:

- At small scales, normalized shapes can differ greatly across bases;
- As magnitude increases, nearest-magnitude JS distance generally shrinks substantially;
- But the interval boundaries do not coincide exactly, so this can only be a descriptive audit.

For example, near decimal \(L_5\):

```text
base 2  matched scale: JS ≈ 5.55e-4
base 8  matched scale: JS ≈ 7.8e-5
base 16 matched scale: JS ≈ 9.1e-5
```

At this finite magnitude, the normalized shapes are already very close.

---

# 10. The three layers actually distinguished in this round

We can now clearly distinguish:

## A. Ontology-level property

\[
\operatorname{Prime}(n)
\]

does not depend on the base.

## B. Scale-robust finite phenomenon

Similar directions still appear after changing the base, such as the current observations:

```text
high-scale center bias remains negative
adjacent normalized shapes become more similar
```

These are only candidates for deeper structure.

## C. Representation-sensitive geometry

For example:

```text
exact center-bias magnitude
scale count
scale widths
which primes fall in the same block
exact histogram shape at fixed finite k
```

all depend significantly on the scale grammar.

---

# 11. A new DMSD classification

This round can provisionally define:

### Projection Artifact

Appears only in one base / scale grammar.

### Projection-Sensitive Quantity

Exists across bases, but its numerical value changes systematically.

### Cross-Projection Persistent Pattern

Retains the same direction or form in finite validation across multiple bases.

### Projection Invariant

Requires stronger proof; it cannot be claimed from finite cross-base persistence alone.

Therefore:

\[
\boxed{
\text{Persistent}
\neq
\text{Invariant}.
}
\]

This distinction is important.

---

# 12. DMSD's original Representation Audit passes its first practical trial

In Phase 1, we merely stipulated:

> Decimal patterns must be checked in other bases.

Now that we have actually carried it out, the result is not “everything is a decimal artifact”:

```text
全部是 decimal artifact
```

nor is it “everything is invariant”:

```text
全部都是 invariant
```

Instead, it is a more reasonable intermediate result:

\[
\boxed{
\text{Some directions survive across bases,
but projection values and local geometry remain highly base-sensitive.}
}
\]

This is precisely the information a representation audit should provide.

---

# 13. Reinterpreting the Phase 3B center bias

The previous round observed:

\[
B_{10,k}<0.
\]

Looking only at decimal scales can easily raise the question:

> Is there a special decimal prime geometry?

After changing the base, the negative sign still appears.

The more reasonable hypothesis now becomes:

> This may primarily come from prime density decreasing from left to right within a multiplicative interval, rather than from a uniquely decimal regularity.

This is the value of the cross-base audit:

\[
\boxed{
\text{It changes our explanation of what causes the pattern.}
}
\]

---

# 14. The next step should not be to guess a theorem immediately

The most natural next round is not:

> “Prove that center bias is always negative.”

Instead, first move on to:

# DMSD Phase 3D — Scale-Normalized Density Model

Incorporate the known density-decay baseline,
for example by constructing a simple reference profile:

\[
w(x)\propto\frac1{\log x}.
\]

Then ask:

> After removing the known first-order effect that “prime density decreases with x,” what residual structure remains in the local-position histogram?

In other words, from:

\[
H_{\text{observed}}
\]

separate:

\[
H_{\text{baseline}}
\]

and:

\[
H_{\text{residual}}.
\]

This will be cleaner than looking for patterns directly in the raw histogram.

---

# 15. Conclusion

The most important result of this round is:

\[
\boxed{
\text{Prime ontology survives base change trivially,
but prime projection geometry does not.}
}
\]

At the same time, the current finite exact data show that two trends:

\[
\boxed{
\text{negative normalized center bias}
}
\]

and:

\[
\boxed{
\text{increasing adjacent-scale shape similarity}
}
\]

do not immediately disappear in base 2 / 8 / 10 / 16.

They therefore merit further baseline removal,
but are still entirely insufficient to be called base-independent invariants.

Here, DMSD's representation audit truly fulfills its purpose for the first time:

> **Not merely to find attractive plots, but to actively ask: how much of an attractive plot remains when we change the space in which we view it?**

---

```text
DMSD Phase 3C: COMPLETE
Validation: PASS

Next:
DMSD Phase 3D — Scale-Normalized Density Model
```
