Boundary Conditions as Dirac Constraints

In this article we show that \BCs can be treated as \Lag and \Ham primary constraints. Using the Dirac method, we find that \BCs are equivalent to an infinite chain of second class \con which is a new feature in the context of constrained systems. We discuss the Dirac brackets and the reduced phase space structure for different boundary conditions. We also show that in a quantized field theory subjected to the mixed boundary conditions, the field components are noncommutative