In the IIA case
the 11th dimension is a circle, whereas in the HE case it is a
line interval (so that the eleven-dimensional space-time has two ten-dimensional
(S1 denotes a circle and I denotes a line interval.)
There are many additional dualities that arise when more dimensions are compactified, which will not be described here.
| Contents | Resolving Contradictions | Supersymmetry | A Brief History of Superstings |
| Basic Ideas of Superstring Theory | Superstring Revolution, part deux |