Entanglement Entropy and Causal Set Theory

We review a formulation of the entanglement entropy of a quantum scalar field in terms of its spacetime two-point correlation functions. We discuss applications of this formulation to studying entanglement entropy in various settings in causal set theory. These settings include sprinklings of causal diamonds in various dimensions in flat spacetime, de Sitter spacetime, massless and massive theories, multiple disjoint regions, and nonlocal quantum field theories.