Notes on exact solvability for rotating and pulsating strings in nonrelativistic Lifshitz background

TL;DR

This paper develops an exactly solvable model of rotating and pulsating strings in Lifshitz spacetime, revealing integrability conditions and deriving energy-momentum relations with implications for spin chain models.

Contribution

It constructs a new exactly solvable string model in Lifshitz backgrounds and analyzes its integrability and physical implications.

Findings

Model reduces to Neumann-Rosochatius integrable form

Classical integrability is conditional due to anisotropy

Derived energy-momentum relations linked to spin chains

Abstract

We construct one dimensional exactly solvable model by choosing a probe fundamental string rotating and pulsating in the planar Lifshitz spacetime that follows nonrelativistic Lifshitz scaling. We present suitable sets of embedding coordinates for rotating and pulsating strings to embed the string worldsheet on a hyperboloid with anisotropy-dependent eccentricity. The resulting worldsheet Lagrangians straightforwardly reduce to the Lagrangian of a Neumann-Rosochatius integrable model. Although the model assumes exact solutions for both the chosen ansatz its classical Liouville integrability is found to be conditional due to the presence of finite anisotropy in the target space geometry. We further use the exact solutions of the model to yield energy-momentum dispersion relations. We interpret those from the perspective of highly degenerate frustrated $J_1-J_2$ spin chain for rotating string and frustration-free Motzkin spin chain for pulsating string.