Radiation from an accelerated quark via AdS/CFT correspondence

In this paper we investigate radiation by an accelerated quark in a strongly coupled gauge theory via anti-de Sitter/conformal field theory (AdS/CFT) correspondence. According to the AdS/CFT dictionary, we can read off the energy density or energy flux of the radiation from the asymptotic gravitational field in AdS bulk sourced by an accelerated string trailing behind the quark. In the case of an oscillating quark with frequency Omega, we show that the time averaged energy density is asymptotically isotropic, and it falls off as (g(YM)(2)N)(1/2)Omega(4)/R-2 with distance R from the source. In a toy model of a scattered quark by an external field, we simply estimate the Poynting vector by the bremsstrahlung radiation and show that the energy flux is anisotropic outgoing radiation. Based on these investigations, we discuss the properties of strongly coupled gauge theory radiation in comparison with electromagnetic radiation.