Mostow Rigidity

Geometric rigidity, volume invariance, Margulis thickness
topologicaldim 35 metrics

What It Measures

Whether your signal's geometry is locked in place or free to deform -- the difference between a crystal and a liquid.

Embeds byte triples into the 3D Poincaré ball, forms tetrahedra, and then asks: if you shake the data slightly, does the hyperbolic geometry change? Mostow's rigidity theorem says that in dimension 3 and above, the shape of a hyperbolic manifold is completely determined by its topology -- there are no continuous deformations. This geometry tests the discrete analog: whether small perturbations (5% Gaussian noise) alter the distance structure, volume distribution, and spectral properties.

Metrics

distance_rigidity

Correlation between the original and perturbed pairwise distance matrices. Rule 30 (0.985) and Symbolic Lorenz (0.984) are nearly rigid: shaking the input barely changes the distances. This means their structure is determined by the combinatorial pattern, not the exact byte values. Constants score 0.0 (no distances to correlate).

volume_entropy

Shannon entropy of the hyperbolic tetrahedron volume distribution. Beta Noise (4.52), XorShift32 (4.50), and Dice Rolls (4.50) produce the most varied volumes -- their points fill the ball uniformly, creating tetrahedra of many different sizes. Logistic Period-2 (0.0) produces identical tetrahedra.

volume_rigidity

How stable is the total hyperbolic volume under perturbation? AES Encrypted (0.97) and Gzip (0.96) are volume-rigid: noise barely changes their total volume. Lorenz and Rössler Attractors score 0.0 -- their attractor geometry is sensitive to perturbation, the volumes shift substantially.

margulis_ratio

Ratio of 5th-percentile to 95th-percentile pairwise distances. Measures the gap between thin and thick parts of the geometry. Logistic Period-2 (1.0) has perfectly uniform spacing. Pulse-Width Mod (0.91) is nearly uniform. Low values mean the signal has both tightly clustered and widely separated regions.

spectral_rigidity

Correlation between Laplacian eigenvalues before and after perturbation. L-System Dragon (1.0), Morse Code (1.0), and Symbolic Henon (1.0) have perfectly stable spectra -- their graph connectivity pattern is insensitive to small perturbations. Logistic Period-3 (0.33) has a fragile spectrum.

Atlas Rankings

distance_rigidity
SourceDomainValue
Rule 30exotic0.9848
Symbolic Lorenzexotic0.9843
Rule 110exotic0.9839
···
Constant 0xFFnoise0.0000
Constant 0x00noise0.0000
Logistic r=3.83 (Period-3 Window)chaos0.0000
margulis_ratio
SourceDomainValue
Logistic r=3.2 (Period-2)chaos1.0000
Square Wavewaveform0.9801
Pulse-Width Modulationwaveform0.9145
···
Constant 0xFFnoise0.0000
Constant 0x00noise0.0000
Logistic r=3.83 (Period-3 Window)chaos0.0000
spectral_rigidity
SourceDomainValue
L-System (Dragon Curve)exotic1.0000
Morse Codewaveform1.0000
Symbolic Henonexotic0.9999
···
Constant 0xFFnoise0.0000
Constant 0x00noise0.0000
Logistic r=3.83 (Period-3 Window)chaos0.3347
volume_entropy
SourceDomainValue
Beta Noisenoise4.5196
XorShift32binary4.4984
Dice Rollsexotic4.4975
···
Constant 0xFFnoise0.0000
Constant 0x00noise0.0000
Logistic r=3.2 (Period-2)chaos0.0000
volume_rigidity
SourceDomainValue
AES Encryptedbinary0.9699
Gzip (level 1)binary0.9641
Dice Rollsexotic0.9610
···
Lorenz Attractorchaos0.0000
Rossler Attractorchaos0.0000
Constant 0xFFnoise0.0000

When It Lights Up

Mostow Rigidity uniquely separates signals whose geometric structure is topologically determined from those that are metrically flexible. The volume_rigidity metric cleanly splits encrypted/compressed data (rigid, 0.96+) from dynamical attractors (flexible, near 0.0) -- a distinction no other geometry captures. The distance_rigidity metric at the top is dominated by cellular automata and symbolic dynamics, signals whose structure is entirely combinatorial.

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