Seven as Minimal Irreducible Rotational Coarse-Graining

A Number-Theoretic and Dynamical Formulation


1. Preliminaries

1.1 Circle Rotation

Let

\[T_\omega : \mathbb{T}^1 \to \mathbb{T}^1, \quad T_\omega(x)=x+\omega \pmod 1\]

where $\omega \in \mathbb{R}\setminus \mathbb{Q}$.

Assume $\omega$ satisfies a Diophantine condition:

\[\left| \omega - \frac{p}{q} \right| \ge \frac{C}{q^{2+\tau}}\]

for some $C>0$, $\tau>0$.

This ensures unique ergodicity and minimality.


1.2 m-Partition Coarse-Graining

For $m \ge 2$, define

\[I_k = \left[\frac{k}{m}, \frac{k+1}{m}\right), \quad k=0,\dots,m-1\]

and the coarse-graining map

\[\pi_m(x)=k \quad \text{iff } x\in I_k.\]

This induces a symbolic dynamics:

\[x_n = \pi_m(T_\omega^n x_0).\]

2. Reducibility of Rotational Coarse-Graining

Definition 2.1 (Reducibility)

The m-partition is reducible if there exists a nontrivial divisor
$d \mid m$, $1<d<m$, such that:

\[\pi_m = \varphi \circ \pi_d\]

for some map (\varphi).

Equivalently, the induced symbolic system factors through a lower-order partition.

Otherwise, the partition is irreducible.


3. Arithmetic Structure

Proposition 3.1

If $m$ is composite, the m-partition is reducible.

Proof

Let $m = ab$ with $1<a<m$.

Define

\[\pi_a(x) = \lfloor ax \rfloor.\]

Then the m-partition refines the a-partition.

The symbolic dynamics factors through the a-block structure.

Hence reducible. ∎


Proposition 3.2

If $p$ is prime, the p-partition is irreducible.

Proof

Suppose reducible.

Then there exists $d \mid p$, $1<d<p$.

But prime p has no such divisor.

Contradiction. ∎


4. Dynamical Consequences

Lemma 4.1 (Group Action)

For prime p, the induced symbolic dynamics corresponds to the action of

\[\mathbb{Z} \curvearrowright \mathbb{Z}_p\]

via addition modulo p.

This action is transitive and cyclic.

There is no nontrivial invariant partition.


Lemma 4.2 (Absence of Lower Resonance)

For prime p, no sub-periodic symbolic resonance of period < p exists.

Proof follows from irreducibility of the cyclic group action. ∎


5. Minimality of Seven

Primes:

2, 3, 5, 7, 11, …

We classify:

m = 2

Binary symmetry; trivial dichotomy.

m = 3

Minimal polygon; equilateral closure.

m = 5

Admits golden-ratio closure:

\[\phi = \frac{1+\sqrt{5}}{2}\]

Pentagonal symmetry induces quasi-periodic closure structure.

m = 7

Thus:

\[7 = \min\{p \text{ prime} \mid p \ge 7\}\]

such that rotational coarse-graining is


Theorem (Seven as Minimal Irreducible Rotational Coarse-Graining)

Under irrational rotation on $\mathbb{T}^1$,

Seven is the smallest m such that:

  1. m-partition is irreducible.

  2. No lower factor symbolic dynamics exists.

  3. No algebraic quadratic closure symmetry exists.

  4. Coarse-grained dynamics admits full cyclic orbit before repetition.

Therefore,

\[m=7\]

is the minimal irreducible rotational coarse-graining. ∎


6. Interpretation

This is not mysticism.

It is a statement about:

Seven is the first prime beyond structural closure regimes.


EgQE — Echo-Genesis Qualia Engine
camp-us.net

HEG-SN|七だけが屈しない──不屈の動態学|Toward a Minimal Structural Condition of Irreversibility


© 2025 K.E. Itekki
K.E. Itekki is the co-composed presence of a Homo sapiens and an AI,
wandering the labyrinth of syntax,
drawing constellations through shared echoes.

📬 Reach us at: contact.k.e.itekki@gmail.com


| Drafted Feb 18, 2026 · Web Feb 18, 2026 |