Casimir effect between world-branes in heterotic M-theory

Abstract

We study a non-supersymmetric E 8 × E 8 compactification of M-theory on S 1 /Z 2 , related to the supersymmetric E 8 × E 8 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 E 8 and E 8 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 E 8 × E 8 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.

Theory and phenomenology of type I strings and M-theory

“…The effect of the nontrivial Bianchi identity is to produce potential terms for moduli fields such that the 5d theory becomes a gauged SUGRA [33]. The spectrum on the two boundaries depends on the solution chosen for (67). For example, the standard embedding solution m 1 = p 1 = p 2 and m 2 = 0 gives a gauge group E 6 on one boundary with h (1,1) chiral multiplets in the fundamental representation 27 of E 6 and h (2,1) chiral multiplets in the 27, while the other boundary hosts a super YangMills theory with gauge group E 8 .…”

Casimir force in Randall-Sundrum models

“…Previous studies have analyzed cosmological aspects of the vacuum, such as the cosmological constant as a manifestation of the Casimir energy during the primordial cosmic inflation [12]. The Casimir energy has been investigated in the context of string theories [13], and even in Randall Sundrum models, as means of stabilizing the radion [14]. The dynamical Casimir effect has also been discussed in warped braneworlds [15].…”

Spacelike and Time Dependent Branes from DBI

“…Specifically we analytically continue the volcano solution of the previous section and obtain an analogue of Witten's bubble of nothing. This is a DBI approach to brane and anti-brane annihilation with some similarities to the supergravity approach discussed by Fabinger and Horava [21]. They studied a non-supersymmetric E 8 × E 8 compactification of M theory on S 1 /Z 2 and proposed that spacetime could semiclassically annihilate due to wormholes nucleating between the two E 8 boundaries.…”