Disclination dynamics in nematic liquid crystals

This paper presents a simple particle plus field model for the dynamics of disclination lines in a nematic liquid crystal. The model has no logarithmic divergences with system size and, therefore, no need to introduce a cutoff. The resulting equation of motion relates the velocity of the disclination to the local phase gradient at the core of the disclination. The equation is used to obtain a solution, with a scaling behavior at small time for the annihilation of a pair of opposite strength disclinations. In addition, this paper develops a criterion for the flow speed required to free a disclination from the boundary constraints of the container.