# Reduced qKZ equation: general case

## TL;DR

This paper derives a generalized reduced quantum Knizhnik-Zamolodchikov equation using quantum group methods to study correlation functions in integrable models for any simple Lie algebra, applicable at all temperatures.

## Contribution

It introduces a new functional equation for the inhomogeneous reduced density matrix in integrable models, extending the qKZ framework to the general case.

## Key findings

- Derivation of the reduced qKZ equation for arbitrary simple Lie algebras.
- Framework applicable to correlation functions at any temperature.
- Potential for analyzing ground state properties in integrable systems.

## Abstract

We use the quantum group approach for the investigation of correlation functions of integrable vertex models and spin chains. For the inhomogeneous reduced density matrix in case of an arbitrary simple Lie algebra we find functional equations of the form of the reduced quantum Knizhnik-Zamolodchikov equation. This equation is the starting point for the investigation of correlation functions at arbitrary temperature and notably for the ground state.