# Punctured Haag duality in locally covariant quantum field theories

February 10, 2004

We investigate a new property of nets of local algebras over 4-dimensional
globally hyperbolic spacetimes, called punctured Haag duality. This property
consists in the usual Haag duality for the restriction of the net to the causal
complement of a point $p$ of the spacetime. Punctured Haag duality implies Haag
duality and local definiteness. Our main result is that, if the theory is
locally covariant in the sense of Brunetti, Fredenhagen and Verch, then also
the converse holds. The free Klein-Gordon field provides an example in which
this property is verified.

Keywords:

locally covariant QFT, QFT on curved spacetimes, Haag duality