A 2D integrable axion model and Target space duality

TL;DR

This paper reviews a 2D axion model with a Hopf-term, explores its T-duality with an anisotropic sigma-model, and provides strong evidence for the proposed S-matrix through perturbative and Bethe Ansatz calculations, testing quantum T-duality.

Contribution

It introduces a new 2D axion model with a dynamical Hopf-term and demonstrates its T-duality with an anisotropic sigma-model, validating the S-matrix and quantum duality.

Findings

Strong evidence for the proposed S-matrix from Bethe Ansatz comparisons

Validation of T-duality at the quantum level through energy calculations

Quantum non-integrability of the non-dynamical Hopf-term sigma-model

Abstract

A review is given on the recently proposed two dimensional axion model (O(3) sigma-model with a dynamical Hopf-term) and the T-duality relating it to the SU(2)xU(1) symmetric anisotropic sigma-model. Strong evidence is presented for the correctness of the proposed S-matrix for both models comparing perturbative and Thermodynamical Bethe Ansatz calculations for different types of free energies. This also provides a very stringent test of the validity of T-duality transformation at the quantum level. The quantum non-integrability of the O(3) sigma-model with a non-dynamical Hopf-term, in contradistinction to the axion model, is illustrated by calculating the 2-->3 particle production amplitude to lowest order.