The Geometry

What falls out of the model without being put in.


Hyperbolic space

Define the “information distance” between two particles as dI = −log MI(A,B). This converts entanglement strength into a geometric distance: strongly entangled particles are close, weakly entangled ones are far.

The geometry defined by dI is hyperbolic. Specifically, the Gromov boundary of the infinite binary tree — the set of all infinite paths from the root — maps to the boundary of the hyperbolic plane H². This is not an assumption. It is a mathematical theorem about the structure of infinite trees.

Hyperbolic geometry is the natural geometry of anti-de Sitter (AdS) space — the setting in which the most developed theories of quantum gravity (the AdS/CFT correspondence) operate. The Quantum Family Tree model reproduces AdS geometry from nothing but a binary branching rule.

The holographic entropy formula

In 2006, Shinsei Ryu and Tadashi Takayanagi proved that the entropy of a region of space is proportional to the area of the minimal surface separating it from the rest. This is the Ryu-Takayanagi (RT) formula, and it is the centerpiece of modern holography.

In the Quantum Family Tree model, the RT formula holds: the expected mutual information between a region of leaves and its complement equals the number of edges cut by the minimal tree cut. The formula falls out of the tree structure without any additional assumptions.

Ryu-Takayanagi (annealed)
E[I(A:B)] ∝ |minimal cut|
The holographic entropy formula emerges from genealogical structure.

Ultrametricity

Real physical space obeys the triangle inequality: the distance from A to C is at most the distance from A to B plus B to C. But the information distance in our model obeys something stronger: the ultrametric inequality, which says the distance from A to C is at most the maximum of the A-to-B and B-to-C distances.

We tested this on 1 million random triples of particles in a depth-8 tree. Ultrametricity holds for 98.3% of all triples, with a standard deviation of 0.006 across trees.

Ultrametric spaces are the natural home of p-adic numbers — a mathematical structure that has appeared repeatedly in string theory and quantum gravity. The model independently lands in the same mathematical class.


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