1303.4428 (Brian Greene et al.)

Tumbling through a landscape: Evidence of instabilities in
high-dimensional moduli spaces    [PDF]

Brian Greene, David Kagan, Ali Masoumi, Erick J. Weinberg, Xiao Xiao

We argue that a generic instability afflicts vacua that arise in theories whose moduli space has large dimension. Specifically, by studying theories with multiple scalar fields we provide numerical evidence that for a generic local minimum of the potential the usual semiclassical bubble nucleation rate, Gamma = A exp(-B), decreases rapidly as function of the number of fields in the theory. As a consequence, the fraction of vacua with tunneling rates low enough to maintain metastability appears to fall as a double exponential of the moduli space dimension. We discuss possible implications for the landscape of string theory. Notably, if our results prove applicable to string theory, the landscape of metastable vacua would not contain sufficient diversity to offer a natural explanation of dark energy.

View original: http://arxiv.org/abs/1303.4428