Target space entanglement entropy

A bstract We define a notion of target space entanglement entropy. Rather than partitioning the base on which theory is defined, we consider partitions space. This physical case interest for first-quantized theories, such as worldsheet string theory. associate to each subregion suitably chosen subalgebra observables $$ \mathcal{A} A . The entropy calculated density matrix restricted As an example, illustrate our framework by computing spatial in many-body quantum mechanics. algebra reproduce obtained embedding state fixed particle sub-sector second-quantized Hilbert then generalize construction field-theoretical setting.