It is shown that for some special values of Hamiltonian parameters the Tomonaga-Luttinger model with nonlinear dispersion is unitary equivalent to the system of noninteracting fermions. For such parameter values the density-density propagator of the Tomonaga-Luttinger Hamiltonian with nonliner dispersion can be found exactly. In a generic situation the exact solution can be used as a reference point around which a perturbative expansion in orders of certain irrelevant operators may be constructed.
|Journal||Physical Review B - Condensed Matter and Materials Physics|
|Publication status||Published - 2006|