Golden-Mean β-Shift

symbolic-dynamics · 37 views
symbolic-dynamicssymbolic

What It Is

Greedy β-expansion digits of a random x in [0,1) at base β = φ ≈ 1.618 (golden ratio). The φ-β-shift is the golden-mean shift of finite type --- the binary sequences with no two consecutive 1s --- which is SOFIC (recognized by a 2-state labeled graph). Topological entropy log φ ≈ 0.481. The sofic pole of a matched-entropy soficity contrast: paired with the Gap-Word β-Shift (non-sofic, β ≈ 1.55) it holds entropy roughly fixed while soficity varies, testing whether the atlas separates sofic from non-sofic beyond entropy / complexity.

Interpretation

Standard analysis sees: few distinct values; anti-correlated (alternating); blue spectrum (high-frequency power); homoskedastic; low-dimensional. The atlas finds no named structure, but the source is distinctively extreme on Hyperbolic (Poincaré):temporal_variance (+4.0z) — beyond what the standard bank predicts for it. It sits beside Symbolic Henon in the atlas (standard-bank rank 28) — a neighbor conventional features miss.

What standard analysis sees
tail heaviness0.37
asymmetry0.81
occupancy0.03
short-range corr0.09
long-range memory0.21
spectral colour0.91
periodicity0.24
complexity0.30
time-irreversibility0.51
volatility clustering0.04
multifractality0.34
dimensionality0.00
nonstationarity0.16
What the atlas adds
Atlas-extreme metrics the standard bank can’t predict for this source
Hyperbolic (Poincaré):temporal_variance+4.0zbank-miss 1.1σ
Nonstationarity:dynamic_coupling+3.9zbank-miss 1.1σ
Marginal:tail_occupancy_r1_5+3.3zbank-miss 2.7σ

Composition

dtypeuint8
range[0, 255]
unique values2 / 16384
mean ± std69.9 ± 114

Binary sequence — two distinct symbols.

Render Gallery

Atlas Position

Nearest neighborDistance
Gap-Word β-Shift1.99
Collatz Parity2.53cross-origin
Symbolic Henon3.75cross-origin

Open in Atlas →

Which Geometries Light Up

Boltzmann › Boltzmann:nn_dominancerank 1/3063.7918
Hyperbolic (Poincaré) › Hyperbolic (Poincaré):temporal_variancerank 3/30618.3853
Marginal › Marginal:tail_occupancy_r1_5rank 2/3060.2763
Nonstationarity › Nonstationarity:dynamic_couplingrank 3/3069.3620
Ulam Spiral (Square) › Ulam Spiral (Square):radon_anisotropyrank 306/3060.0001
Visibility Graph › Visibility Graph:degree_exponent_gammarank 5/3062.6610
Zariski › Zariski:residual_convexityrank 2/30614.5110
in number-theory
alphabetical
← / → within domain · ⇧← / ⇧→ alphabetical · ⇧← / ⇧→ inside an open render = same view across sources