Electromagnetic response in supersymmetric Yang-Mills fluid

Supersymmetric Yang-Mills theory is an example of a four-dimensional gauge theory where thermal current-current spectral functions can be calculated analytically at both weak and strong coupling. This allows one to track how electromagnetic response quantities such as photon production rate and electrical conductivity change as the coupling varies from the perturbative g2Nc≪1 to the non-perturbative g2Nc→∞ regime. We discuss potential lessons which may be drawn for QCD.