Beyond The Quenched (or Probe Brane) Approximation in Lattice (or   Holographic) QCD
  We propose a method to improve the quenched approximation. The method, based on the worldline formalism, takes into account effects of quark loops. The idea is useful mostly for AdS/CFT (holographic) calculations. To demonstrate the method we estimate screening (string breaking) effects by a simple holographic calculation. 
Adi Armoni