text: 90,33,940252195051659264,21611239,Sean Carroll,"How quantum entanglement can define the geometry of spacetime, and gravity can emerge from the wave function. New paper with Charles Cao. <LINK> @active_50 @realDonaldTrump I’m sure he has thoughts. @RobJLow Ooh that’s good. Totally stealing that. (Will try to remember to attribute!)",https://arxiv.org/abs/1712.02803,"We consider the emergence from quantum entanglement of spacetime geometry in a bulk region. For certain classes of quantum states in an appropriately factorized Hilbert space, a spatial geometry can be defined by associating areas along codimension-one surfaces with the entanglement entropy between either side. We show how Radon transforms can be used to convert this data into a spatial metric. Under a particular set of assumptions, the time evolution of such a state traces out a four-dimensional spacetime geometry, and we argue using a modified version of Jacobson's ""entanglement equilibrium"" that the geometry should obey Einstein's equation in the weak-field limit. We also discuss how entanglement equilibrium is related to a generalization of the Ryu-Takayanagi formula in more general settings, and how quantum error correction can help specify the emergence map between the full quantum-gravity Hilbert space and the semiclassical limit of quantum fields propagating on a classical spacetime. ","Bulk Entanglement Gravity without a Boundary: Towards Finding Einstein's