No-Drag String Configurations for Steadily Moving Quark-Antiquark Pairs   in a Thermal Bath
  We investigate the behavior of stationary string configurations on a five-dimensional AdS black hole background which correspond to quark-antiquark pairs steadily moving in an N=4 super Yang-Mills thermal bath. There are many branches of solutions, depending on the quark velocity and separation as well as on whether Euclidean or Lorentzian configurations are examined. 
Philip C. Argyres, Mohammad Edalati and Justin F. Vazquez-Poritz