Holographic Thermalization at Intermediate Coupling

We use the AdS/CFT conjecture to investigate the thermalization of large-Nc N=4 super Yang-Mills plasma in the limit of large but finite 't Hooft coupling. On the gravity side, we supplement the type IIB supergravity action by the full set of O(α^'3) operators, which enables us to derive O(λ^-3/2) corrections to the emission spectrum of prompt photons in one model of holographic thermalization. Decreasing the coupling strength from the λ=∞ limit, we observe a qualitative change in the way the photon spectral density approaches its thermal limit as a function of the photon energy. We interpret this behavior as a sign of the thermalization pattern of the plasma shifting from top-down towards bottom-up.