Complexity and Multi-boundary Wormholes in 2+1 dimensions

Three dimensional wormholes are global solutions of Einstein-Hilbert action. These space-times which are quotients of a part of global AdS(3) have multiple asymptotic regions, each with conformal boundary S-1 x R, and separated from each other by horizons. Each outer region is isometric to BTZ black hole, and behind the horizons, there is a complicated topology. The main virtue of these geometries is that they are dual to known CFT states. In this paper, we evaluate the full time dependence of holographic complexity for the simplest case of 2 + 1 dimensional Lorentzian wormhole spacetime, which has three asymptotic AdS boundaries, using the "complexity equals volume" (CV) conjecture. We conclude that the growth of complexity is non-linear and saturates at late times.