D-branes and twelve dimensions Original Research Article

We study the D-brane solutions to a type IIB superstring in ten dimensions and find an interpretation in terms of the compactification of a twelve-dimensional three-brane of (a specific) F-theory on torus T2. In this framework, there also exists a two-brane which may be argued to be equivalent to the three-brane by utilizing the electric-magnetic duality in eleven dimensions. In this context, we propose the existence of an isometry in one of the transverse directions to the three-brane in F-theory. As a consequence the two-brane may be identified with the three-brane in twelve dimensions. The twelve-dimensional picture of D-branes in type IIB theory suggests the reformulation of the type IIB superstring in terms of the three-brane of F-theory.