Special Holonomy Manifolds in Physics
  This is a pedagogical exposition of holonomy groups intended for physicists. After some pertinent definitions, we focus on special holonomy manifolds, two per division algebras, and comment upon several cases of interest in physics, associated with compactification from F-, M- and string theory, on manifolds of 8, 7 and 6 dimensions respectively. 
Luis J. Boya