A Review of Casimir Supported Traversable Wormhole and Warp Drive Spacetimes*

The idea of super-luminal travel has been explored ever since the laws of special and general relativity were proposed [Davis, Prog.Astronaut.Aeronaut. (2009)]. There are two primary classes of solutions to Einstein’s equations that produce super-luminal travel; traversable wormholes and warp drives. Traversable wormholes were first explored by Morris and Thorne [American Journal of Physics 56, 395 (1988)] under static and spherically symmetric conditions, but have since been expanded to more general solutions [Visser, Lorentzian Wormholes (1996)]. Warp drives were first proposed by Alcubierre [Class.Quant.Grav.11:L73-L77,1994] and then expanded on by others, in particular Natario [Class.Quant.Grav. 19 (2002)], Lobo [Fundam.Theor.Phys. 189 (2017)], and Van De Broek [Class.Quant.Grav. 16 (1999)]; but still remain a poorly understood class of solutions.

Even though wormholes and warp drives are two fundamentally different classes of solutions, there is a common thread for both; the requirement for the existence of negative energy density (NED). NED remains an open question in physics, especially pertaining to the limits on the quantities of NED that can be created and exist. However, we do know of one experimentally confirmed form of NED, the Casimir energy. First proposed by Casimir, its simplest form is negative energy density arising from quantum fluctuations inside a cavity formed by two neutral parallel plates. Since we can create Casimir energy, it of interest as a potential source of NED for wormholes and warp drives. As such, there has been some extensive work done on using the Casimir energy as the source of NED.

I review the work that has been done in researching the Casimir energy as a source for wormholes and warp drives; as well as provides possible new avenues of research into this area. Specifically, I review the theorized properties of traversable wormholes and warp drives supported by Casimir energy in relation to their general relativistic properties, their applications to classical and quantum energy condition violations, faster than light travel, materials physics, and quantum computing. I also give avenues for future work.