Phi-Squared 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 = φ² = (3+√5)/2 ≈ 2.618. The expansion of 1 is 2·1^∞ (eventually periodic but infinite), so this β-shift is SOFIC BUT NOT a shift of finite type --- the strictly-sofic middle of the Parry trichotomy (SFT ⊂ sofic ⊂ general subshift). Ternary alphabet, entropy log φ² ≈ 0.962. A higher-entropy sofic anchor for the soficity probe, alongside the Golden-Mean β-Shift.

Composition

dtypeuint8
range[0, 255]
unique values3 / 16384
mean ± std92 ± 94.3

Fixed alphabet — only 3 distinct symbols across 16384 samples.

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Atlas Position

Nearest neighborDistance
Moebius Function3.77cross-origin
Free Group F₂ Walk3.81
Codon Usage4.03cross-origin

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Which Geometries Light Up

CayleyCayley:delta_hyp_normrank 4/3070.2627
CayleyCayley:growth_exponentrank 306/3070.6794
NonstationarityNonstationarity:change_quantiles_highrank 4/3070.2350
ZariskiZariski:algebraic_residualrank 4/3070.0652
ZariskiZariski:residual_sloperank 305/307-5.7127
in stochastic-process
alphabetical
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