MPHA Seminar, Blocker 627, 30th November 2007, 1:50pm Speaker: Maxim Zyskin, UT Brownsville Title: Liquid crystals in polyhedral domains Liquid crystal configurations in polyhedra with tangent boundary conditions can be described by maps from a contractible polyhedra to a sphere, which maps faces of polyhedra to great circles of the sphere. Homotopy classification of such maps can be given in terms of certain homotopy invariants. Stable configuration of liquid crystal are harmonic maps corresponding to local minima of Dirichlet energy functional. We discuss lower/upper bounds for infimum energy for such maps in a fixed homotopy class. Lower bounds can be given in terms of certain lengths of minimal connections, but in some cases that can be improved. This work has applications to new type of liquid crystal displays.