par Machet, Ludovico ;Wang, Jinzhao
Référence Classical and quantum gravity, 38, 8, 085004
Publication Publié, 2021-04-01
Article révisé par les pairs
Résumé : We discuss how to define a kinematical horizon entropy on a causal set. We extend a recent definition of horizon molecules to a setting with a null hypersurface crossing the horizon. We argue that, as opposed to the spacelike case, this extension fails to yield an entropy local to the hypersurface-horizon intersection in the continuum limit when the causal set approximates a curved spacetime. We then investigate the entropy defined via the spacetime mutual information between two regions of a causal diamond truncated by a causal horizon, and find it does limit to the area of the intersection.