N = 2 supergravity models with gauge Kac-Moody groups

In this paper we consider a class of models for vector and hypermultiplets, interacting with $N=2$ supergravity, with gauge groups being an infinite-dimensional Kac-Moody groups. It is shown that specific properties of Kac-Moody groups, allowing the introduction of the vector fields masses without the usual Higgs mechanism, make it possible to break simultaneously both the supersymmetry and the gauge symmetry. Also, a kind of inverse Higgs mechanism can be realized, that is, in the considered model there exists a possibility to lower masses of the scalar fields, which usually acquire huge masses as a result of supersymmetry breaking. That allows one to use them, for example, as Higgs fields at the second step of the gauge symmetry breaking in the unified models.