Generalized Number Theoretic Spin Chain-Connections to Dynamical Systems and Expectation Values

TL;DR

This paper extends the number theoretic spin chain model by introducing a parameter, revealing connections to dynamical systems and enabling explicit calculation of expectation values related to phase transitions.

Contribution

It introduces a generalized spin chain model with a new parameter, linking it to dynamical systems and providing explicit formulas for expectation values.

Findings

Connection to the Lewis three-term equation

Explicit calculation of spin expectation values

Relation to phase transition mechanisms

Abstract

We generalize the number theoretic spin chain, a one-dimensional statistical model based on the Farey fractions, by introducing a new parameter x>=0. This allows us to write recursion relations in the length of the chain. These relations are closely related to the Lewis three-term equation, which is useful in the study of the Selberg \zeta-function. We then make use of these relations and spin orientation transformations. We find a simple connection with the transfer operator of a model of intermittency in dynamical systems. In addition, we are able to calculate certain spin expectation values explicitly in terms of the free energy or correlation length. Some of these expectation values appear to be directly connected with the mechanism of the phase transition.