One of the most intriguing and fundamental questions is a formation of  Quark Ggluon Plasma (QGP). Experimentally, QGP is created in the heavy ion collisions. A quest for QGP is the driving force behind two major experimental programs, one at the  Relativistic Heavy Ion Collider (RHIC) and  another one at the LHC.

Among most striking recent discoveries is the observation made at the RHIC that QGP produced there at temperatures about twice the QCD critical temperature is in fact strongly coupled. The  RHIC data  indicate that QGP at not too high temperatures behaves like a nearly perfect fluid with relativistic hydrodynamics being an appropriate description of the observed phenomena. Remarkably, gauge theories at strong coupling can be studied using the AdS/CFT duality: from the string theory point of view, QGP is holographically dual to weakly coupled string theory in the 5-dimensional  Anti-de-Sitter (AdS) Black Hole background metric.  Many interesting phenomena relevant for heavy ion collisions can be learn from the (super) gravity approximation to the string theory. In particular by studying graviton`s absorption into the AdS Black Hole within Einstein`s general relativity, one can learn a great deal about dissipative processes taking place in QGP.