QCD viscosity by combining the gradient flow and sparse modeling methods

TL;DR

This paper introduces a novel approach to accurately determine the shear viscosity in finite-temperature QCD by combining gradient flow and sparse modeling techniques to analyze correlation functions.

Contribution

It presents a new methodology that integrates gradient flow and sparse modeling to improve the precision of shear viscosity calculations in QCD.

Findings

Successful extraction of the correlation function using gradient flow.

Effective estimation of spectral functions via sparse modeling.

Potential for more precise shear viscosity measurements in QCD.

Abstract

We give a new description to obtain the shear viscosity in QCD at finite temperature. Firstly, we obtain the correlation function of the renormalized energy-momentum tensor using the gradient flow method. Secondly, we estimate the spectral function from the smeared correlation functions using the sparse modeling method. The combination of these two methods looks promising to determine the shear viscosity precisely.