Information transfer with a gravitating bath

Abstract

Late-time dominance of entanglement islands plays a critical role in addressing the information paradox for black holes in AdS coupled to an asymptotic non-gravitational bath. A natural question is how this observation can be extended to gravitational systems. To gain insight into this question, we explore how this story is modified within the context of Karch-Randall braneworlds when we allow the asymptotic bath to couple to dynamical gravity. We find that because of the inability to separate degrees of freedom by spatial location when defining the radiation region, the entanglement entropy of radiation emitted into the bath is a time-independent constant, consistent with recent work on black hole information in asymptotically flat space. If we instead consider an entanglement entropy between two sectors of a specific division of the Hilbert space, we then find non-trivial time-dependence, with the Page time a monotonically decreasing function of the brane angle---provided both branes are below a particular angle. However, the properties of the entropy depend discontinuously on this angle, which is the first example of such discontinuous behavior for an AdS brane in AdS space.

Submerging islands through thermalization

“…Correspondingly, at late times we can expect islands to appear in both black hole regions. Similar models were considered in [11,25,26]. See [38,39] for a discussion of entanglement between disjoint gravitating universes.…”

“…For further developments of the doubly holographic approach to the entanglement entropy of radiation, see e.g [14,[19][20][21][22][23][24][25][26],. especially[20] for a pedagogical treatment.…”

Universal relations for holographic interfaces

“…There have been quite a few recent studies of RT surfaces in RS spacetimes in the context of entanglement islands, for example [32][33][34][35]. In this context, one usually first solves the RT surface in the un-deformed spacetime away from the brane and then imposes a nontrivial gluing condition for the RT surface across the brane.…”

Conformal bootstrap near the edge

“…There are several similar (but different) holographic setups where a wedge plays a role. We find of note, the wedge holography between AdS d+1 and CFT d−1 of [56], the interface-type holography studied in [57,58] and others in the entanglement entropy literature [59][60][61]. For a more direct relation it would be interesting to construct a holographic setup dual to the wedge configuration.…”