Entanglement of Dirac fields in an expanding spacetime

TL;DR

This paper investigates how the expansion of a 2D universe differently affects entanglement in Dirac (fermionic) and bosonic fields, revealing fermionic entanglement encodes more spacetime information.

Contribution

It demonstrates that fermionic fields encode more detailed information about spacetime expansion than bosonic fields, highlighting the importance of particle statistics in relativistic quantum entanglement.

Findings

Fermionic entanglement encodes more information about spacetime.

Qualitative differences between bosonic and fermionic entanglement.

Fermionic entanglement can reconstruct expansion parameters.

Abstract

We study the entanglement generated between Dirac modes in a 2-dimensional conformally flat Robertson-Walker universe. We find radical qualitative differences between the bosonic and fermionic entanglement generated by the expansion. The particular way in which fermionic fields get entangled encodes more information about the underlying space-time than the bosonic case, thereby allowing us to reconstruct the parameters of the history of the expansion. This highlights the importance of bosonic/fermionic statistics to account for relativistic effects on the entanglement of quantum fields.