Integrable coupled bosonic massive Thirring model and its nonlocal reductions

TL;DR

This paper introduces a new integrable coupled bosonic massive Thirring model and constructs five novel nonlocal integrable models through reductions, confirming their integrability via Lax pairs and conserved quantities.

Contribution

The paper presents the first integrable coupled bosonic massive Thirring model and derives five new nonlocal integrable models with various symmetries and conserved quantities.

Findings

Constructed Lax pairs for all models.

Derived infinite conserved quantities confirming integrability.

Identified symmetry properties of the models.

Abstract

A coupled bosonic massive Thirring model (BMTM), involving an interaction between the two independent spinors, is introduced and shown to be integrable. By incorporating suitable reductions between the field components of the coupled BMTM, five novel integrable models with various type of nonlocal interactions are constructed. Lax pairs satisfying the zero curvature condition are obtained for the coupled BMTM and for each of the related nonlocal models. An infinite number of conserved quantities are derived for each of these models which confirms the integrability of the systems. It is shown that the coupled BMTM respects important symmetries of the original BMTM such as parity, time reversal, global $U(1)$-gauge and the proper Lorentz transformations. Similarly, all the nonlocal models obtained from the coupled BMTM remain invariant under combined operation of parity and time reversal transformations. However, it is found that only one of the nonlocal models is invariant under proper Lorentz transformation and two other models are invariant under global $U(1)$-gauge transformation. By using ultralocal Poisson bracket relations among the elements of the Lax operator, it is shown that the coupled BMTM and one of the nonlocal models are completely integrable in the Liouville sense.