KCL-MTH-04-03 hep-th/0402140 The IIA, IIB and eleven dimensional theories and their common E11 origin.

We show that the commonly considered half BPS solutions of eleven dimensional super-gravity and the ten dimensional type II theories, when expressed in terms of E 11 group elements, take the universal form exp(− 1 2 lnN β · H) exp((1 − N)E β). Using this formula we find new potential solutions to the E 11 non-linearly realisations corresponding to active fields which are beyond those in the supergravity approximations. These include the space filling nine brane of the IIB theory. We use E 11 to give a correspondence between the fields of the eleven dimensional and the IIA and IIB non-linear realisations without assuming any dimensional reduction. As one consequence, we find the eleven dimensional origin of the eight brane solution of the massive IIA theory.