Casimir effect between world-branes in heterotic M-theory Original Research Article

We study a non-supersymmetric E8×E8 compactification of M-theory on S1/Z2, related to the supersymmetric E8×E8 theory by a chirality flip at one of the boundaries. This system represents an M-theory analog of the D-brane anti-D-brane systems of string theory. Alternatively, this compactification can be viewed as a model of supersymmetry breaking in the “brane-world” approach to phenomenology. We calculate the Casimir energy of the system at large separations, and show that there is an attractive Casimir force between the E8 and E8 boundary. We predict that a tachyonic instability develops at separations of order the Planck scale, and discuss the possibility that the M-theory fivebrane might appear as a topological defect supported by the E8×E8 system. Finally, we analyze the eventual fate of the configuration, in the semiclassical approximation at large separations: the two ends of the world annihilate by nucleating wormholes between the two boundaries.