Jack Sarfatti Subject: ER = EPR

Susskind & Maldecena here show that traversable wormholes and entanglement signal nonlocality are two sides of the same coin. I anticipated all this in 1973-4.

"Spacetime locality is one of the cornerstones in our present understanding of physics. By locality we mean the impossibility of sending signals faster than the speed of light. Locality appears to be challenged both by quantum mechanics and by general relativity. Quantum mechanics gives rise to Einstein Podolsky Rosen (EPR) correlations [1], while general relativity allows solutions to the equations of motion that connect far away regions through relatively short “wormholes” or Einstein Rosen bridges [2]. It has long been understood that these two effects do not give rise to real violations of locality. One cannot use EPR correlations to send information faster than the speed of light. Similarly, Einstein Rosen bridges do not allow us to send a signal from one asymptotic region to the other, at least when suitable positive energy conditions are obeyed [3, 4, 5]. This is sometimes stated as saying that Lorentzian wormholes are not traversable1.

Here we will note that these two effects are actually connected. We argue that the Einstein Rosen bridge between two black holes is created by EPR-like correlations between the microstates of the two black holes. This is based on previous observations in [6, 10]. We call this the ER = EPR relation. In other words, the ER bridge is a special kind of EPR correlation in which the EPR correlated quantum systems have a weakly coupled Einstein gravity description. It is also special because the combined state is just one particular entangled state out of many possibilities. We note that black hole pair creation in a magnetic field “naturally” produces a pair of black holes in this state. It is very tempting to think that any EPR correlated system is connected by some sort of ER bridge, although in general the bridge may be a highly quantum object that is yet to be independently defined. Indeed, we speculate that even the simple singlet state of two spins is connected by a (very quantum) bridge of this type.

In this article we explain the reasons for expecting such a connection. We also explore some of the implications of this point of view for the black hole information problem, in its AMPS(S)[11, 12] form. See [13, 14, 15] for some earlier work and [12] for a more complete set of references. See [16] for a proposal to describe interiors that is similar to what we are saying here2."

Cool horizons for entangled black holes

Juan Maldacena1 and Leonard Susskind2

1 Institute for Advanced Study, Princeton, NJ 08540, USA

2 Stanford Institute for Theoretical Physics and Department of Physics,

Stanford University, Stanford, CA 94305-4060, USA