Self-organized criticality in quantum gravity

TL;DR

This paper investigates a simple spin network evolution model inspired by self-organized criticality, suggesting that classical space-time may emerge from microscopic quantum dynamics through a natural critical process.

Contribution

It introduces a model of spin network evolution that demonstrates self-organized criticality, providing a potential mechanism for space-time emergence without fine tuning.

Findings

Certain evolution rules lead to scale-invariant correlation functions.

The model exhibits behavior analogous to sand pile models.

Evidence of critical states emerging naturally in the system.

Abstract

We study a simple model of spin network evolution motivated by the hypothesis that the emergence of classical space-time from a discrete microscopic dynamics may be a self-organized critical process. Self organized critical systems are statistical systems that naturally evolve without fine tuning to critical states in which correlation functions are scale invariant. We study several rules for evolution of frozen spin networks in which the spins labelling the edges evolve on a fixed graph. We find evidence for a set of rules which behaves analogously to sand pile models in which a critical state emerges without fine tuning, in which some correlation functions become scale invariant.