Non-fock linear boson systems and their applications in two-dimensional models

A method is proposed for “dressing” some non-Fock boson systems equipped with an Abelian group of gauge transformations of the first kind; the vacuum of the system is induced by the Fock vacuum of the algebra of gauge-invariant variables. A twodimensional free scalar field with zero mass is considered as an example of such a system; the process of bosonization of the (massless) Thirring field is described in terms of this field.