Solitones en la teoría Einstein--Maxwell--dilatón--axión

Abstract

In the present research work we obtain solitonic solutions by means of two of the most successful nonlinear techniques of the modern physics: the inverse scattering method and the application of Lie--Bäcklund symmetries. We show that these techniques can be applied in the framework of the four--dimensional low--energy effective field theory of the heterotic string better known as Einstein--Maxwell--dilaton--axion theory. Thus, we obtain an exact soliton solution for the field equation of the chiral matrix $P$, which involves the $g_{tt}$--component of the tensor field, the dilaton and a electric field, starting from pure flat space--time. We further apply a nonlinear symmetry of the full effective theory on this soliton solution in order to generate a new field configuration which also involves the pseudoscalar field axion, a magnetic field and the $g_{t \phi}$--component of the metric tensor (which describes gravitational rotation). We analize as well some properties of these solitonic configurations.