AQFT and operator algebra
Given a local net of observables
a natural algebra endomorphism
is called local or localized if outside of a bounded region of spacetime it is the identity.
Localized endomorphisms play a central role in DHR superselection theory.
An endomorphim is localized or localizable if there is a bounded open set such that is the identity on the algebra of the causal complement . Such an endomorphism is localized in .