We describe the construction of traversable wormholes with multiple mouths in four spacetime dimensions and discuss associated quantum entanglement. Our wormholes may be traversed between any pair of mouths. In particular, in the three-mouth case they have fundamental group F₂ (the free group on two generators). By contrast, connecting three regions A, B, C in pairs (AB, BC, and AC) using three separate wormholes would give fundamental group F₃. Our solutions are asymptotically flat up to the presence of possible magnetic fluxes or cosmic strings that extend to infinity. The construction begins with a two-mouth traversable wormhole supported by backreaction from quantum fields. Inserting a sufficiently small black hole into its throat preserves traversability between the original two mouths. This black hole is taken to be the mouth of another wormhole connecting the original throat to a new distant region of spacetime. Making the new wormhole traversable in a manner similar to the original two-mouth wormhole provides the desired causal connections. From a dual field theory point of view, when AdS asymptotics are added to our construction, multiparty entanglement may play an important role in the traversability of the resulting wormhole.

我们在四个时空维度上描述了具有多个嘴的可穿越虫洞的构造，并讨论了相关的量子纠缠。我们的虫洞可以在任何一对嘴之间穿行。特别是在三嘴情况下，它们具有基本群F ₂（两个发电机上的自由群）。相比之下，使用三个单独的虫洞成对地连接三个区域A，B，C（AB，BC和AC）将得到基本群F _3。。我们的解决方案在渐近趋近于可能延伸到无穷大的可能的磁通量或宇宙弦的情况下趋于平坦。该构造始于一个两口可穿越的虫洞，该虫洞由量子场的反向反应支撑。在其喉咙中插入足够小的黑洞可保留原始两个嘴之间的可遍历性。这个黑洞被认为是另一个蠕虫的嘴巴，它将原来的喉咙连接到了一个新的时空遥远区域。使新的虫洞以与原始的两口虫洞类似的方式可遍历，可以提供所需的因果关系。从双场理论的观点来看，当将AdS渐近性添加到我们的构造中时，多方纠缠可能在所产生的虫洞的可遍历性中发挥重要作用。