Local exact controllability to the trajectories of the liquid crystal flow and global null controllability of the liquid crystal flow with an external field

This dissertation encompasses my research work during my Ph.D. career, focusing on the controllability properties of liquid crystal flow. I have achieved two main results, which are as follows: Firstly, I have established the local exact controllability to the trajectory of the simplified Ericksen-Leslie model and its Ginzburg-Landau approximation. Secondly, I have successfully proven the global null controllability of the simplified Ericksen-Leslie model with Lions boundary condition for u and Neumann boundary condition for d, with the aid of a globally defined magnetic field which is independent of the spatial variable x.