  We review the results of refs. [1,2], in which the entanglement entropy in
spaces with horizons, such as Rindler or de Sitter space, is computed using
holography. This is achieved through an appropriate slicing of anti-de Sitter
space and the implementation of a UV cutoff. When the entangling surface
coincides with the horizon of the boundary metric, the entanglement entropy can
be identified with the standard gravitational entropy of the space. For this to
hold, the effective Newton's constant must be defined appropriately by
absorbing the UV cutoff. Conversely, the UV cutoff can be expressed in terms of
the effective Planck mass and the number of degrees of freedom of the dual
theory. For de Sitter space, the entropy is equal to the Wald entropy for an
effective action that includes the higher-curvature terms associated with the
conformal anomaly. The entanglement entropy takes the expected form of the de
Sitter entropy, including logarithmic corrections.
