Gap-Word 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 ≈ 1.55, fixed by the aperiodic admissibility word 1 0 1 00 1 000 … (a 1 then a growing run of 0s). Because the β-expansion of 1 is aperiodic, β is a non-Parry number and the β-shift is NON-SOFIC: its Fischer cover (the number of distinct follower sets) grows without bound. Topological entropy log β ≈ 0.438, near-matched to the Golden-Mean β-Shift (sofic, β ≈ 1.618). The non-sofic pole of the matched-entropy contrast --- and, unlike the Sturmian words, non-sofic at POSITIVE entropy via the orbit-of-1 mechanism rather than an irrational rotation.

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 2-adic:distance_entropy (-2.7z) — beyond what the standard bank predicts for it. It sits beside Symbolic Henon in the atlas (standard-bank rank 40) — a neighbor conventional features miss.

What standard analysis sees
tail heaviness0.54
asymmetry0.84
occupancy0.02
short-range corr0.12
long-range memory0.16
spectral colour0.91
periodicity0.21
complexity0.27
time-irreversibility0.51
volatility clustering0.06
multifractality0.85
dimensionality0.00
nonstationarity0.17
What the atlas adds
Atlas-extreme metrics the standard bank can’t predict for this source
2-adic:distance_entropy-2.7zbank-miss 1.2σ
Marginal:tail_occupancy_r1_5+2.3zbank-miss 2.7σ

Composition

dtypeuint8
range[0, 255]
unique values2 / 16384
mean ± std56.8 ± 106

Binary sequence — two distinct symbols.

Render Gallery

Atlas Position

Nearest neighborDistance
Golden-Mean β-Shift1.99
Collatz Parity2.96cross-origin
Symbolic Henon3.78cross-origin

Open in Atlas →

Which Geometries Light Up

Fisher Information › Fisher Information:log_det_fisherrank 5/306137.6196
Fisher Information › Fisher Information:trace_fisherrank 5/306229605.7445
Moiré › Moiré:moire_invariance_breadthrank 304/3060.0031
Moiré › Moiré:moire_max_coherencerank 306/3060.0207
Mostow Rigidity › Mostow Rigidity:margulis_ratiorank 3/3060.9247
Nonstationarity › Nonstationarity:dynamic_couplingrank 2/3069.3779
Time Reversibility › Time Reversibility:ordinal_reversal_distancerank 303/3060.0002
Time Reversibility › Time Reversibility:increment_skewness_maxrank 305/3060.0002
Zariski › Zariski:residual_convexityrank 1/30614.5227
Zariski › Zariski:heyting_gaprank 5/3060.8119
in symbolic-dynamics
alphabetical
← / → within domain · ⇧← / ⇧→ alphabetical · ⇧← / ⇧→ inside an open render = same view across sources