  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.

High Energy Physics - Theory