Coarse-grained entropy and causal holographic information in AdS/CFT

A bstract We propose bulk duals for certain coarse-grained entropies of boundary regions. The ‘one-point entropy’ is defined in the conformal field theory by maximizing the entropy in a domain of dependence while fixing the one-point functions. We conjecture that this is dual to the area of the edge of the region causally accessible to the domain of dependence (i.e. the ‘causal holographic information’ of Hubeny and Rangamani). The ‘future onepoint entropy’ is defined by generalizing this conjecture to future domains of dependence and their corresponding bulk regions. We show that the future one-point entropy obeys a nontrivial second law. If our conjecture is true, this answers the question “What is the field theory dual of Hawking’s area theorem?”