Plane symmetric traversable wormholes in an anti–de Sitter background

We construct solutions of plane symmetric wormholes in the presence of a negative cosmological constant by matching an interior spacetime to the exterior anti–de Sitter vacuum solution. The spatial topology of this plane symmetric wormhole can be planar, cylindrical, or toroidal. As usual, the null energy condition is necessarily violated at the throat. At the junction surface, the surface stresses are determined. By expressing the tangential surface pressure as a function of several parameters, namely, the matching radius, the radial derivative of the redshift function, and the surface energy density, the sign of the tangential surface pressure is analyzed. We then study four specific equations of state at the junction: the zero surface energy density, the constant redshift function, the domain wall equation of state, and the traceless surface stress-energy tensor. The equation governing the behavior of the radial pressure, in terms of the surface stresses and the extrinsic curvatures, is also displayed. Finally, we construct a model of a plane symmetric traversable wormhole which minimizes the usage of the exotic matter at the throat, i.e., the null energy condition is made arbitrarily small at the wormhole throat, while the surface stresses on the junction surface satisfy the weak energy condition, and consequently the null energy condition. The construction of these wormholes does not alter the topology of the background spacetime (i.e., spacetime is not multiply connected), so that these solutions can instead be considered domain walls. Thus, in general, these wormhole solutions do not allow time travel.