Spectral sum rules for the quark-gluon plasma

TL;DR

This paper derives spectral sum rules for the stress-energy tensor in N=4 super-Yang-Mills and pure Yang-Mills theories, linking hydrodynamics and high-momentum behavior to aid in constraining quark-gluon plasma properties.

Contribution

It introduces new spectral sum rules connecting hydrodynamic and high-momentum regimes in gauge theories, useful for QGP transport coefficient analysis.

Findings

Sum rules derived for N=4 super-Yang-Mills and pure Yang-Mills theories.

Potential to constrain QGP transport coefficients from lattice QCD.

Links between hydrodynamic behavior and spectral density at large momenta.

Abstract

We derive sum rules involving the spectral density of the stress-energy tensor in N=4 super-Yang-Mills theory and pure Yang-Mills theory. The sum rules come from the hydrodynamic behavior at small momenta and the conformal (in the case of N=4 SYM theory) or asymptotically free (as for the pure Yang-Mills theory) behavior at large momenta. These sum rules may help constrain QGP transport coefficients obtained from lattice QCD.