# Asymptotics of thermal spectral functions - High Energy Physics - Phenomenology

Abstract: We use operator product expansion OPE techniques to study the spectralfunctions of currents and stress tensors at finite temperature, in thehigh-energy time-like region $\omega\gg T$. The leading corrections to thesespectral functions are proportional to $\sim T^4$ expectation values ingeneral, and the leading corrections $\sim g^2T^4$ are calculated at weakcoupling, up to an undetermined coefficient in the shear viscosity channel.Spectral functions are shown to be infrared safe, in the deeply virtual regime,up to order $g^8T^4$. The convergence of vacuum subtracted sum rules in theshear and bulk viscosity channels is established in QCD to all orders inperturbation theory, though numerically significant tails $\simT^4-\log\omega^3$ are shown to exist in the bulk viscosity channel. We arguethat the spectral functions of currents and stress tensors in infinitelycoupled $\mathcal{N}=4$ super Yang-Mills do not receive any medium-dependentpower correction.

Author: S. Caron-Huot

Source: https://arxiv.org/