Probing the pattern of holographic thermalization with photons

A bstract We investigate the behavior of the retarded Green’s function of a U(1) gauge field in holographic = 4 Super Yang-Mills plasma, taking the leading strong coupling corrections into account. First, we use the thermal limit of this quantity to determine the flow of the photon quasinormal mode spectrum away from the infinite ’t Hooft coupling limit, and after this specialize to a specific model of holographic thermalization, in which we evaluate the corresponding spectral density. In the latter case, our primary interest lies in the pattern, with which the spectral density approaches its equilibrium form, and how this process depends on the value of the coupling as well as the photon virtuality. All of the results obtained point consistently towards the weakening of the usual top-down pattern of holographic thermalization, once the coupling is decreased from the λ = ∞ limit.