Application of Polynomial Algorithms to a Random Elastic Medium
  A randomly pinned elastic medium in two dimensions is modeled by a disordered fully-packed loop model. The energetics of disorder-induced dislocations is studied using exact and polynomial algorithms from combinatorial optimization. Dislocations are found to become unbound at large scale, and the elastic phase is thus unstable giving evidence for the absence of a Bragg glass in two dimensions. 
Chen Zeng (Rutgers) and Paul L. Leath (Rutgers)