Target space entanglement entropy

Abstract We define a notion of target space entanglement entropy. Rather than partitioning the base space on which the theory is defined, we consider partitions of the target space. This is the physical case of interest for first-quantized theories, such as worldsheet string theory. We associate to...

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Bibliographic Details
Main Authors: Edward A. Mazenc, Daniel Ranard
Format: Article
Language:English
Published: SpringerOpen 2023-03-01
Series:Journal of High Energy Physics
Subjects:
Online Access:https://doi.org/10.1007/JHEP03(2023)111
Description
Summary:Abstract We define a notion of target space entanglement entropy. Rather than partitioning the base space on which the theory is defined, we consider partitions of the target space. This is the physical case of interest for first-quantized theories, such as worldsheet string theory. We associate to each subregion of the target space a suitably chosen subalgebra of observables A $$ \mathcal{A} $$ . The entanglement entropy is calculated as the entropy of the density matrix restricted to A $$ \mathcal{A} $$ . As an example, we illustrate our framework by computing spatial entanglement in first-quantized many-body quantum mechanics. The algebra A $$ \mathcal{A} $$ is chosen to reproduce the entanglement entropy obtained by embedding the state in the fixed particle sub-sector of the second-quantized Hilbert space. We then generalize our construction to the quantum field-theoretical setting.
ISSN:1029-8479