Mesonic quasinormal modes of the Sakai-Sugimoto model at high temperature

Abstract

We examine the mesonic thermal spectrum of the Sakai-Sugimoto model of holographic QCD by finding the quasinormal frequencies of the supergravity dual. If flavour is added using D8 and anti-D8 branes there exist embeddings where the D-brane worldvolume contains a black hole. For these embeddings (the high-temperature phase of the Sakai-Sugimoto model) we determine the quasinormal spectra of scalar and vector mesons arising from the worldvolume DBI action of the D-brane. We stress the importance of a coordinate change that makes the in-falling quasinormal modes regular at the horizon allowing a simple numerical shooting technique. Finally we examine the effect of finite spatial momentum on quasinormal spectra.