Standard model with compactified spatial dimensions
  We analyze the structure of the standard model coupled to gravity with spatial dimensions compactified on a three-torus. We find that there are no stable one-dimensional vacua at zero temperature, although there does exist an unstable vacuum for a particular set of Dirac neutrino masses. 
Bartosz Fornal, Mark B. Wise
hep-th astro-ph.CO hep-ph