Quantum Gates to Other Universes

We present a microscopic model of a bridge connecting two large Anti-de-Sitter Universes. The Universes admit a holographic description as three-dimensional N = 4 supersymmetric gauge theories based on large linear quivers, and the bridge is a small rank-n gauge group that acts as a messenger. On the gravity side, the bridge is a piece of a highly-curved AdS(5)xS(5) throat carrying n units of five-form flux. We derive a universal expression for the mixing of the two massless gravitons: M-2 similar to 3n(2) (kappa(2)(4) + kappa'(2)(4))/16 pi(2), where M is the mass splitting of the gravitons, kappa(2)(4), kappa'(2)(4) are the effective gravitational couplings of the AdS(4) Universes, and n is the quantized charge of the gate. This agrees with earlier results based on double-trace deformations, with the important difference that the effective coupling is quantized. We argue that the apparent non-localities of holographic double-trace theories are resolved by integrating-in the (scarce) degrees of freedom of the gate.