Spin Entanglement Sharing in Dilaton Spacetime

Abstract

We investigate the influence of the Hawking effect on quantum entanglement by incorporating the spin degrees of freedom of Dirac fields in the background of a Garfinkle–Horowitz–Strominger (GHS) dilaton black hole. By analyzing the redistribution of correlations between causally accessible and inaccessible regions, we obtain analytical results showing that, as the dilaton increases, the physically accessible spin entanglement decreases monotonically while the inaccessible counterpart grows correspondingly, revealing a constrained transfer of quantum correlations across the event horizon rather than independent creation or destruction. From an information‐theoretic perspective, we demonstrate that the Hawking effect does not permit arbitrary redistribution of spin entanglement, but instead enforces a well‐defined monogamy relation that strictly governs how entanglement is shared among different bipartitions under gravitational evolution. These results indicate that the correlations initially shared by the observers are redistributed between accessible and inaccessible sectors through the Hawking‐induced Bogoliubov transformation, providing further insight into the structure of spin quantum correlations in curved spacetime and the role of horizon‐induced effects in reshaping quantum correlations.