Properties of Supermembrane Axions
  In the presence of membranes, M-theory becomes in the low energy limit 11 dimensional supergravity action coupled to a supermembrane action. The fields of the first action are the same fields which couple to the membrane. It is shown that the axionic moduli of the membrane obtained by wrapping the three form potential about three-cycles of a Calabi-Yau manifold can take nonzero integer values. This novel property allows M-theory to have smooth transition from the Kahler cone of a geometrical phase to a Kahler cone of another geometrical phase. Nongeometrical phases which define the boundary of the extended Kahler cone of the geometrical phases have discrete spectrum, and are continuously connected to the geometric phases. Using this new property, we relate the M-theory model dependent axion to the type IIA model dependent axion and show that a potential develops for the type IIA axion in the strong coupling regime which does not seem to be generated by instantons. Evidence is presented, using these moduli, which supports the Strominger conjecture on the winding p-branes. 
F. Aldabe