Hedgehog annihilation in a confined nematic liquid crystal

Annihilation of a pair of nematic point defects, having opposite strength is studied numerically. The defects are enclosed within an infinite cylindrical cavity whose lateral wall enforces strong homeotropic anchoring. The Lebwohl-Lasher lattice model is used. The dynamics of the system consisting of N > 10(5) molecules is studied using the Brownian molecular dynamics. We study pre-collision, collision and post-collision regimes. In the first regime the defects are well separated and are clearly distinguishable. Latter the core structures of defects strongly overlap and gradually decay into the defectless state.